InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 3901. |
Which figure is formed by three noncollinear points? |
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Answer» Three non-collinear points form a triangle. |
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| 3902. |
The following table shows points on a number line and their co-ordinates. Decide whether the pair of segments given below the table are congruent or not.PointABCDECo-ordinate-352-79i. seg DE and seg ABii. seg BC and seg ADiii. seg BE and seg AD |
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Answer» i. Co-ordinate of the point E is 9. Co-ordinate of the point D is -7. Since, 9 > -7 ∴ d(D, E) = 9 – (-7) = 9 + 7 = 16 ∴ l(DE) = 16 …(i) Co-ordinate of the point A is -3. Co-ordinate of the point B is 5. Since, 5 > -3 ∴ d(A, B) = 5 – (-3) = 5 + 3 = 8 ∴ l(AB) = 8 …(ii) ∴ l(DE) ≠ l(AB) …[From (i) and (ii)] ∴ seg DE and seg AB are not congruent ii. Co-ordinate of the point B is 5. Co-ordinate of the point C is 2. Since, 5 > 2 ∴ d(B, C) = 5 – 2 = 3 ∴ l(BC) = 3 …(i) Co-ordinate of the point A is -3. Co-ordinate of the point D is -7. Since, -3 > -7 ∴ d(A, D) = -3 – (-7) = -3 + 7 = 4 ∴ l(AD) = 4 . ..(ii) ∴ l(BC) ≠ l(AD) … [From (i) and (ii)] ∴ seg BC and seg AD are not congruent. iii. Co-ordinate of the point E is 9. Co-ordinate of the point B is 5. Since, 9 > 5 ∴ d(B, E) = 9 – 5 = 4 ∴ l(BE) = 4 …(i) Co-ordinate of the point A is -3. Co-ordinate of the point D is -7. Since, -3 > -7 ∴ d(A, D) = -3 – (-7) = 4 ∴ l(AD) = 4 …(ii) ∴ l(BE) =l(AD) …[From (i) and (ii)] ∴ seg BE and seg AD are congruent. i.e, seg BE ≅ seg AD |
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| 3903. |
If x denotes the digit at hundreds place of the number \(\overline{67\times19}\) such that the number is divisible by 11. Find all possible values of x. |
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Answer» Here, given number is \(\overline{67\times19}\) . We know that a number is divisible by 11 if and only if the difference between the sum of odd and even place digits is a multiple of 11. ∴ Sum of even placed digits – Sum of odd placed digits = 0, 11, 22,… ∴ (6 + x + 9) – ( 7+1) = 0, 11, 22,… ∴ x + 7 is a multiple of 11 ∴ x + 7 = 11 ∴ x = 4 |
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| 3904. |
The following table shows points on a number line and their co-ordinates. Decide whether the pair of segments given below the table are congruent or not.PointABCDECo-ordinate-352-79i. seg DE and seg AB ii. seg BC and seg AD iii. seg BE and seg AD |
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Answer» i. Co-ordinate of the point E is 9. Co-ordinate of the point D is -7. Since, 9 > -7 ∴ d(D, E) = 9 – (-7) = 9 + 7 = 16 ∴ l(DE) = 16 …(i) Co-ordinate of the point A is -3. Co-ordinate of the point B is 5. Since, 5 > -3 ∴ d(A, B) = 5 – (-3) = 5 + 3 = 8 ∴ l(AB) = 8 …(ii) ∴ l(DE) ≠ l(AB) …[From (i) and (ii)] ∴ seg DE and seg AB are not congruent. ii. Co-ordinate of the point B is 5. Co-ordinate of the point C is 2. Since, 5 > 2 ∴ d(B, C) = 5 – 2 = 3 ∴ l(BC) = 3 …(i) Co-ordinate of the point A is -3. Co-ordinate of the point D is -7. Since, -3 > -7 ∴ d(A, D) = -3 – (-7) = -3 + 7 = 4 ∴ l(AD) = 4 . ..(ii) ∴ l(BC) ≠ l(AD) … [From (i) and (ii)] ∴ seg BC and seg AD are not congruent. iii. Co-ordinate of the point E is 9. Co-ordinate of the point B is 5. Since, 9 > 5 ∴ d(B, E) = 9 – 5 = 4 ∴ l(BE) = 4 …(i) Co-ordinate of the point A is -3. Co-ordinate of the point D is -7. Since, -3 > -7 ∴ d(A, D) = -3 – (-7) = 4 ∴ l(AD) = 4 …(ii) ∴ l(BE) =l(AD) …[From (i) and (ii)] ∴ seg BE and seg AD are congruent. i.e, seg BE ≅ seg AD |
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| 3905. |
Co-ordinates of some pairs of points are given below. Hence find the distance between each pair.i. 3,6 ii. -9, -1 iii. A, 5 iv. 0,-2 v. x + 3, x – 3 vi. -25, -47 vii. 80, -85 |
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Answer» i. Co-ordinate of first point is 3. Co-ordinate of second point is 6. Since, 6 > 3 ∴ Distance between the points = 6 – 3 = 3 ii. Co-ordinate of first point is -9. Co-ordinate of second point is -1. Since, -1 > -9 ∴ Distance between the points = -1 – (-9) = -1 + 9 = 8 iii. Co-ordinate of first point is -4. Co-ordinate of second point is 5. Since, 5 > -4 ∴ Distance between the points = 5 – (-4) = 5 + 4 = 9 iv. Co-ordinate of first point is 0. Co-ordinate of second point is -2. Since, 0 > – 2 ∴ Distance between the points = 0 – (-2) = 0 + 2 = 2 v. Co-ordinate of first point is x + 3. Co-ordinate of second point is x – 3. Since, x + 3 > x – 3 ∴ Distance between the points = x + 3 – (x – 3) = x + 3 – x + 3 = 3 + 3 = 6 vi. Co-ordinate of first point is -25. Co-ordinate of second point is -47. Since, -25 > -47 ∴ Distance between the points = -25 – (-47) = -25 + 47 = 22 vii. Co-ordinate of first point is 80. Co-ordinate of second point is -85. Since, 80 > -85 ∴ Distance between the points = 80 – (-85) = 80 + 85 = 165 |
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| 3906. |
Find all possible values of y for which the 4-digit number 64y3 is divisible by 9. Also, find the numbers. |
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Answer» We know that if sum of digits of a number is divisible by 9, then the number is divisible by 9. Here, 6 + 4 + y + 3 = multiple of 9 y + 13= 0, 9, 18, … Hence, y + 13 = 18 ∴ y = 5 The number will be 6453. |
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| 3907. |
Find d(A, B), if co-ordinates of A and B are – 2 and 5 respectively. (A) -2 (B) 5 (C) 7 (D) 3 |
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Answer» (C) 7 Since, 5 > -2 ∴ d(A, B) = 5 – (-2) = 5+2 = 7 |
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| 3908. |
What least number must be added to 521 to make it a perfect square? A. 3 B. 4 C. 5 D. 8 |
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Answer» For making 521 a perfect square, we have to add 8 on it as: 521 + 8 = 529 And we know that, \(\sqrt{529}=23\) Hence, option (D) is correct |
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| 3909. |
What least number must be subtracted from 178 to make it a perfect square? A. 6 B. 8 C. 9 D. 7 |
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Answer» For making 178 a perfect square we have to subtract 9 from it as: 178 – 9 = 169 And we know that, \(\sqrt{169}=13\) Therefore, option (C) is correct |
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| 3910. |
How many lines are determined by three distinct points? (A) two(B) three (C) one or three(D) six |
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Answer» Correct option is (C) one or three |
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| 3911. |
How many points are there in the intersection of two distinct lines?(A) infinite (B) two (C) one(D) not a single |
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Answer» Correct option is (C) one |
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| 3912. |
If \(\overline{3\times2}\) is a multiple of 11, where x is a digit, what is the value of x? |
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Answer» Here, given number is \(\overline{3\times2}\) . We know that a number is divisible by 11 if and only if the difference between the sum of odd and even place digits is a multiple of 11. ∴ Sum of even placed digits – Sum of odd placed digits = 0, 11, 22,… ∴ x – ( 3+2) = 0, 11, 22,… ∴ x – 5 is a multiple of 11 ∴ x – 5 = 0 ∴ x = 5 |
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| 3913. |
If x is a digit of the number \(\overline{66784\times}\) such that it is divisible by 9, find possible values of x. |
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Answer» Here it is given that \(\overline{66784\times}\) is divisible by 9. We know that if a number is divisible by 9, then sum of digits must be a multiple of 9. ∴ 6 + 6 + 7 + 8 + 4 + x = multiple of 9 ∴ x + 31 = 0,9,18,27,….. But ‘x’ is a digit, hence, ‘x’ can have value between 0 to 9. ∴ x + 31 = 36. ∴ x = 5 |
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| 3914. |
Given that the number \(\overline{35a64}\) is divisible by 3, where a is a digit, what are the possible values of a? |
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Answer» Here it is given that \(\overline{35a64}\) is divisible by 3. We know that if a number is divisible by 3, then sum of digits must be a multiple of 3. ∴ 3 + 5+a+6+4 = multiple of 3 ∴ a + 18 = 0,3,6,9,12,15,….. But ‘a’ is a digit, hence, ‘a’ can have value between 0 to 9. ∴ a + 18 = 18 which gives a = 0. ∴ a + 18 = 21 which gives a = 3. ∴ a + 18 = 24 which gives a = 6. ∴ a + 18 = 27 which gives a = 9. ∴ a = 0,3,6,9 |
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| 3915. |
If P – Q – R and d(P, Q) = 2, d(P, R) = 10, then find d(Q, R). (A) 12 (B) 8 (C) √96 (D) 20 |
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Answer» (B) 8 d(P, R) = d(P, Q) + d(Q, R) ∴ 10 = 2 + d(Q, R) ∴ d(Q, R) = 8 |
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| 3916. |
Solved each of the following Cryptarithms:\(\frac{\begin{matrix}A & B & 7\\+7 & A & B\end{matrix}}{9\,\,\,\,\,\,\,\,8\,\,\,\,\,\,A}\) |
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Answer» For unit’s place, We have two conditions, when 7 + B ≤ 9 and 7 + B > 9 For 7 + B ≤ 9 7 + B = A ∴ A – B = 7 …(1) In ten’ place, B + A = 8 …(2) Solving 1 and 2 simultaneously, 2A = 15 which means A = 7.5 which is not possible Hence, our condition 7 + B ≤ 9 is wrong. ∴ 7 + B > 9 is correct condition Hence, carrying one in ten’s place and subtracting 10 from unit’s place, 7 + B – 10 = A ∴ B – A = 3 … (3) For ten’s place, B + A + 1 = 8 ∴ B + A =7 …(4) Solving 3 and 4 simultaneously, 2B = 10 ∴ B = 5 and A = 2 |
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| 3917. |
Class 8 Maths MCQ Questions of Squares and Square Roots with Answers? |
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Answer» Students can also reach out to Sarthaks to get Important Questions for Class 8 Maths for all other chapters. Sarthaks eConnect is a platform that provides study materials for students. Multiple Choice Questions for Class 8 are given here. Each problem carries four options, in which one is the correct answer. You can solve the Class 8 Maths MCQ Questions of square and square roots with Answers for your extensive revision for exams. Students have to find a solution for each problem and choose the correct answer. These important questions with solutions will definitely benefit all students with revision and mastering the topic. you will learn the concepts of square and square roots. There are many important questions given for the chapter that will give you an idea of what kind of question you can expect in exams. Practice MCQ Question for Class 8 Maths chapter-wise 1. A perfect square number between 30 and 40 is (a) 36 2. Find perfect square numbers between 50 and 60 (a) 50, 54 3. Which of the following is a perfect square number? (a) 1067 4. Which of 1322, 872, 722, and 2092 would end with digit 1? (a) 1322 5. Which of 1052, 2162, 3332, and 1112 would end with digit 1? (a) 1052 6. What will be the number of zeros in the square of the number 60? (a) 1 7. The square of which of the following numbers will be even? 11, 111, 1111, 112 (a) 11 8. The square of which of the following numbers will be odd ? 10, 100, 1000, 99 (a) 10 9. Write the correct answer from the given four options. How many natural numbers lie between 52 and 62? (a) 9 10. How many numbers lie between the squares of 20 and 21 (a) 10 11. How many non-square numbers lie between the pairs of numbers 1002 and 1012 : (a) 200 12. How many non-square numbers lie between the pairs of numbers 902 and 912 : (a) 200 13. What will be the unit digit of the squares of the number 81? (a) 1 14. The unit digit in the square of the number 1333 is (a) 3 15. The unit digit in the square of the number 166 is (a) 22 16. Which of the following is not a Pythagorean triplet? (a) 3, 4, 5 17. The square root of 441/961 is: (a) 21/39 18. If M is a square number, then the next immediate square number is (a) \(M+2\sqrt M+1\) 19. If a square number ends in 6, the preceding figure is (a) an odd number 20. The smallest number by which 396 must be multiplied so that the product becomes a perfect square is: (a) 5 21. A number added to its square gives 56. The number is: (a) 12 22 .\(\sqrt{\frac{1}{16}+\frac{1}{9}}\) is (a) 5/12 23. Which of the following will have 6 at the unit place? (a) 192 24. The value of 92 – 1 is equal to: (a) 81 25. The Pythagorean triples whose smallest number is 8: (a) 8, 16 17 Answer: 1. Answer: (a) 36 Explanation: Since, 1 x 1 = 1 2 x 2 = 4 3 x 3 = 9 4 x 4 = 16 5 x 5 = 25 6 x 6 = 36 7 x 7 = 49 Thus, 36 is a perfect square number between 30 and 40. 2. Answer: (d) None of the above Explanation: By squaring, we get as 1 → 1 2 → 4 3 → 9 4 → 16 5 → 25 6 → 36 7 → 49 8 → 64 From, this we can say that there is no perfect square between 50 and 60 3. Answer: (d) 625 Explanation: Perfect square numbers end with, 0, 1, 4, 5, 6, or 9 at the unit’s place. 4. Answer: (d) 2092 Explanation: If a number has 1 or 9 in the unit’s place, then its square ends in 1. 5. Answer:(d) 1112 Explanation: If a number has 1 or 9 in the unit’s place, then its square ends in 1. 6. Answer: (b) 2 Explanation: In 60, the number of zero is 1 ∴ Its square will have 2 zeros. 7. Answer: (d) 112 Explanation: ∵ 112 is even ∴ Its square will be even. 8. Answer: (d) 99 Explanation: ∵ 99 is odd ∴ Its square will be odd. 9. Answer: (b) 10 Explanation: Square of 5 = 25 and Square of 6 = 36 Natural numbers lie between 25 and 36 = 26, 27, 28, 29, 30, 31, 32, 33, 34, 35. 10. Answer: (b) 40 Explanation: 202 = 400 212 = 441 ∴number of numbers =(441−400)−1 =40 11. Answer: (a) 200 Explanation: Between 1002 and 1012. Here, n=100 ∴ n x 2 = 100 x 2 = 200 ∴ 200 non-square numbers lie between 1002 and 1012 . 12. Answer: (c) 180 Explanation: Between 902 and 912 Here, n=90 ∴ 2 x n = 2 x 90 or 180 ∴ 180 non-square numbers lie between 90 and 91. 13. Answer: (a) 1 Explanation: 12 = 1. So, the unit digit will be 1. 14. Answer: (c) 9 Explanation: 32 = 9. So, the unit digit will be 9. 15. Answer: (c) 36 Explanation: 62 = 36. So, the unit digit will be 36. 16. Answer: (d) 2, 3, 4 Explanation: 32 + 42 = 52 62 + 82 = 102 52 + 122 = 132 22 + 32 ≠ 42 is not a Pythagorean triplet. 17. Answer: (c) 21/31 Explanation: The square root of 441/961 is \(\frac{\sqrt{144}}{\sqrt{961}}=\frac{21}{31}\) 18. Answer: (a) \(M+2\sqrt M+1\) Explanation: \(M+2\sqrt M+1\) Take M = 4, a Square number. \(M+2\sqrt M+1\) = \(4+2\sqrt4+1\) = 4 + 2 × 2 +1 = 9 19. Answer: (a) an odd number Explanation: Let us take some square numbers ending with 6. Eg: 136,196,256,676,.... By observation, we can say that the preceding figure are odd numbers. 20. Answer: (b) 11 Explanation: 396 = 2 × 2 × 3 × 3 × 11 So 396 should be multiplied by 11 to make the product a perfect square. 21. Answer: (d) 7 Explanation: A number added to its square gives 56. Let the number be x. Hence, x2 +x = 56 ⇒ x2 + x − 56 = 0 ⇒ x2 + 8x − 7x − 56 = 0 ⇒ x(x+8)−7(x+8)=0 ⇒ (x+8)(x−7) = 0 Hence, x=−8 or x=7 22. Answer: (a) 5/12 Explanation: \(\sqrt{\frac{1}{16}+\frac{1}{9}}\) \(\sqrt{\frac{25}{144}}\) = 5/12 23. Answer: (c) 242 Explanation: 242 = 24 x 24 = 576 24. Answer: (b) 80 Explanation: 92 - 1 = 81 – 1 = 80 25. Answer: (c) 8, 15, 17 Explanation: The general form of Pythagorean triplets is 2m, m2-1, m2+1 Given, 2m = 8 So, m = 4 m2 – 1 = 42 - 1 = 16-1 = 15 m2+1 = 42 + 1 = 16+1 = 17 Click here Practice MCQ Question for Squares and Square Roots Class 8 |
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| 3918. |
Simplify:(i) (√59.29 – √5.29)/ (√59.29 + √5.29)(ii) (√0.2304 + √0.1764)/ (√0.2304 – √0.1764) |
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Answer» (i) (√59.29 – √5.29)/ (√59.29 + √5.29) = √59.29 = √5929/ √100 = 77/10 = 7.7 Now, √5.29 = √5.29/ √100 = 23/10 = 2.3 So, (7.7 – 2.3)/ (7.7 + 2.3) = 54/10 = 0.54 (ii) (√0.2304 + √0.1764)/ (√0.2304 – √0.1764) = √0.2304 = √2304/ √10000 = 48/100 = 0.48 Now, √0.1764 = √1764/ √10000 = 42/100 = 0.42 So, (0.48 + 0.42)/ (0.48 – 0.42) = 0.9/0.06 = 15 |
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| 3919. |
A square yard has area 1764m2. From a corner of this yard, another square part of area 784 m2 is taken out for public utility. The remaining portion is divided into equal square parts. What is the perimeter of each of these equal parts? |
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Answer» The area of the remaining portion = 1764 – 784 = 980 m² It is divided into 5, equal square parts ∴ Each square part = \(\frac{980}{5}\) = 196 m2 Area of each square part = 196 m2 (side)2 = 196 side = √196 side = 14. The length of each side of the square = 14m Perimeter = 4 side = 4 × 14 = 56m |
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| 3920. |
Show that the Crptarithm \(4\times\overline{AB} = \overline{CAB}\) does not have any solution. |
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Answer» If B is multiplied by 4 then only 0 satisfies the above condition. Hence, for unit place to satisfy the above condition, we have, B = 0. Similarly for ten’s place, only 0 satisfies. But, AB cannot be 00 as 00 is not a two digit number. So, A and B cannot be equal to 0 Hence, there is no solution satisfying the condition \(4\times\overline{AB}A = \overline{CAB}\) |
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| 3921. |
Find the cube roots of the numbers 3048625, 20346417, 210644875, 57066625 using the fact that(i) 3048625 = 3375 x 729(ii) 20346417 = 9261 x 2197(iii) 210644875 = 42875 x 4913(iv) 57066625 = 166375 x 343 |
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Answer» (i) 3048625 = 3375 x 729 Taking cube root of the whole, we get, = \(\sqrt[3]{3048625}\) = \(\sqrt[3]{3375\times729}\) We know that, = \(\sqrt[3]{ab}\) = \(\sqrt[3]{a\times}\) \(\sqrt[3]{b}\) = \(\sqrt[3]{3048625}\) = \(\sqrt[3]{3375}\) x \(\sqrt[3]{729}\) Now by prime factorization, = \(\sqrt[3]{3\times3\times3\times5\times5\times5}\) x \(\sqrt[3]{9\times9\times9}\) = \(\sqrt[3]{3^3\times5^3}\times\sqrt[3]{9^3}\) = \(\sqrt[3]{3^3}\times\) \(\sqrt[3]{5^3}\times\sqrt[3]{9^3}\) = \(3\times5\times9 = 135.\) (ii) 20346417 = 9261 x 2197 Taking cube root of the whole, = \(\sqrt[3]{20346417}\) = \(\sqrt[3]{9261\times2197}\) We know that, = \(\sqrt[3]{ab}\) = \(\sqrt[3]{a\times}\) \(\sqrt[3]{b}\) = \(\sqrt[3]{9261\times2197}\) = \(\sqrt[3]{9261}\times\) \(\sqrt[3]{2197}\) Now by prime factorization, = \(\sqrt[3]{3\times3\times3\times7\times7\times7}\) \(\times\sqrt[3]{13\times13\times13}\) = \(\sqrt[3]{3^3\times7^3}\times\) \(\sqrt[3]{13^3}\) = \(\sqrt[3]{3^3}\times\) \(\sqrt[3]{7^3}\times\) \(\sqrt[3]{13^3}\) = 3 × 7 × 13 = 273. (iii) 210644875 = 42875 x 4913 Taking cube root of the whole, = \(\sqrt[3]{210644875}\) = \(\sqrt[3]{42875\times4913}\) We know that, = \(\sqrt[3]{ab}\) = \(\sqrt[3]{a\times}\) \(\sqrt[3]{b}\) = \(\sqrt[3]{42875\times4913}\) = \(\sqrt[3]{42875\times}\) \(\sqrt[3]{4913}\) Now by prime factorization, = \(\sqrt[3]{5\times5\times5\times7\times7\times7}\) x \(\sqrt[3]{17\times17\times17}\) = \(\sqrt[3]{5^3\times7^3}\times\) \(\sqrt[3]{13^3}\) = \(\sqrt[3]{5^3}\times\) \(\sqrt[3]{7^3}\times\) \(\sqrt[3]{17^3}\) = \(5\times7\times17 = 595.\) (iv) 57066625 = 166375 x 343 Taking cube root of the whole, we get, = \(\sqrt[3]{57066625}\) = \(\sqrt[3]{166375\times343}\) We know that, = \(\sqrt[3]{ab}\) = \(\sqrt[3]{a\times}\) \(\sqrt[3]{b}\) Now by prime factorization method, = \(\sqrt[3]{5\times5\times5\times11\times11\times11}\)\(\times\sqrt[3]{7\times7\times7}\) = \(\sqrt[3]{5^3\times11^3\times}\) \(\sqrt[3]{7^3}\) = \(\sqrt[3]{5^3}\times\sqrt[3]{11^3}\times\) \(\sqrt[3]{7^3}\) = \(5\times7\times11 = 385.\) |
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| 3922. |
Find the area of a square field if its perimeter is 96m. |
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Answer» Given, perimeter of the square field = 96 m We know that, perimeter of square = 4 × side Then, 96 = 4 × side Side = 96/4 Side = 24 m So, the length of the side of square = 24 m Now, Area of the square field = (side)2 = 242 = 576 m2 ∴The area of the square field is 576m2. |
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| 3923. |
The volume of a cubical box is 474. 552 cubic metres. Find the length of each side of the box. |
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Answer» Given, Volume of a cube = 474.552 cubic metres V = 83, S = side of the cube So, 83 = 474.552 cubic metres = 8 = \(\sqrt[3]{474.552}\) = \(\sqrt[3]{\frac{474552}{1000}}\) = \(\frac{\sqrt[3]{474552}}{\sqrt[3]{1000}}\) On factorising 474552 into prime factors, we get: 474552 = 2×2×2×3×3×3×13×13×13 On grouping the factors in triples of equal factors, we get: 474552 = {2×2×2}×{3×3×3}×{13×13×13} Now taking 1 factor from each group we get: \(\sqrt[3]{474.552}\) = \(\sqrt[3]{{\{2\times2\times2\times\}}\{\times3\times3\times3\}\{13\times13\times13\}}\) = \(2\times3\times13\) = 78 Also, \(\sqrt[3]{1000} = 10\) ∴ \(8 = \frac{\sqrt[3]{474552}}{\sqrt[3]{1000}}\) = \(\frac{78}{10} = 7.8\) So, length of the side is 7.8m. |
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| 3924. |
Find the length of each side of a cube if its volume is 512 cm3. |
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Answer» From the question it is given that, Volume of the cube = 512 cm3 We know that, Volume of cube = side3 512 = side3 By taking cube root on both the side, 3√512 = side Side = 3√(8 × 8 × 8) Side = 3√ (8)3 Side = 8 cm ∴The length of each side of a cube is 8 cm. |
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| 3925. |
If one side of a cube is 15m in length, find its volume. |
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Answer» From the question it is given that, Length of one side of the a cube = 15 m We know that, volume of cube = (side)3 = 153 = 15 × 15 × 15 = 3375 m3 ∴The volume of cube is 3375 m3. |
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| 3926. |
State whether the statements are true (T) or false (F).If a2 ends in 9, then a3 ends in 7. |
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Answer» False. Let a2 be 72 So, 72 = 49 Then, 73 = 343 |
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| 3927. |
State whether the statements are true (T) or false (F).Square root of a number x is denoted by √x. |
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Answer» True. Square root of a number x is denoted by √x. |
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| 3928. |
63, 64, 67, 72, 79,…………… (a) 88 (b) 86 (c) 87 (d) 98 |
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Answer» Correct option is : (a) 88 63, 64, 67, 72, 79, ……….. 63, (63 + 1), (64 + 3), (67 + 5), (72 + 7),…. So, next number is (79 + 9) = 88 |
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| 3929. |
Three numbers are to one another 2:3:4. The sum of their cubes is 0.334125. Find the numbers. |
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Answer» Let the ratio 2:3:4 be 2a, 3a, and 4a. So according to the question: (2a)3+ (3a)3+(4a)3 = 0.334125 8a3+27a3+64a3 = 0.334125 99a3 = 0.334125 a3 = 334125/1000000×99 = 3375/1000000 a = ∛(3375/1000000) = ∛((15×15×15)/ 100×100×100) = 15/100 = 0.15 Hence ,the numbers are: 2×0.15 = 0.30 3×0.15 = 0.45 = 4×0.15 = 0.6 |
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| 3930. |
State whether the statements are true (T) or false (F).Square of a number is positive, so the cube of that number will also be positive. |
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Answer» False. Let us take -3 Now, square of the -3 i.e. -32 = 9 Then, cube of the same number i.e. -33 = -27 |
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| 3931. |
Fill in the blanks to make the statements true.The least number by which 72 be divided to make it a perfect cube is _____________. |
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Answer» 9 Resolving 72 into prime factors, we get Grouping the factors in triplets of equal factors, we get 72 = (2 x 2 x 2) x 3 x 3 Clearly, if we divide 72 by 3 x 3, the quotient would be 2 x 2 x 2, which is a perfect cube. Hence, the least number by which 72 be divided to make it, a perfect cube, is 9. |
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| 3932. |
Difference of two perfect cubes is 189. If the cube root of the smaller of the two numbers is 3, find the cube root of the larger number. |
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Answer» From the question it is given that, Difference of two perfect cubes = 189 The cube root of the smaller of the two numbers = 3 So, cube of smaller number = 33 = 3 × 3 × 3 = 27 Let us assume the cube root of larger number be a3 Then, As per the condition given in the question, a3 – 27 = 189 a3 = 189 + 27 a3 =216 By taking cube root on both side, a = 3√216 a = 3√(6 × 6 × 6) a = 3√(63) a = 6 ∴The cube root of the larger number is 6. |
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| 3933. |
State whether the statements are true (T) or false (F).3√ (8 + 27) = 3√ (8) + 3√ (27). |
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Answer» False. Let us consider LHS = 3√ (8 + 27) = 3√ (35) Then, RHS = 3√8 + 3√27 = 2 + 3 = 5 By comparing LHS and RHS LHS ≠ RHS 3√ (35) ≠ 5 |
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| 3934. |
State whether the statements are true (T) or false (F).The square root of a perfect square of n digits will have (n + 1)/2 digits, if n is odd. |
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Answer» True. Let us assume the perfect square has 9 digits, then its square root has 5 digits i.e. (9 + 1)/2 = 10/2 = 5 |
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| 3935. |
Evaluate: {(52 + (122)1/2)}3 |
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Answer» Given, {(52 + (122)1/2)}3 = {(25 + (144)1/2)}3 = {(25 + (12)}3 = {37}3 = 37 × 37 × 37 = 50,653 |
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| 3936. |
What can be the unit place digit in the square root of the following numbers.(i) 9604(ii) 65536(iii) 998001(iv) 60481729 |
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Answer» (i) Unit place digit in the square root of 9604 = 2,8 (ii) Unit place digit in the square root of 65536 = 4,6 (iii) Unit place digit in die square root of 998001 = 1,9 (iv) Unit place digit in the square root of 60481729 = 3,7 |
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| 3937. |
How many numbers are there in between the following numbers?(i) 10 and 11(ii) 17 and 18(iii) 30 and 31 |
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Answer» (i) 10 + 11 =21 numbers (ii) 17 + 18 = 35 numbers (iii) 30 +31 =61 numbers |
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| 3938. |
Observe the following pattern22 _ 12 = 2+132 - 22 = 3+242 - 32 = 4+352 - 42 = 5+4And find the value of(i) 1002 -992 (ii) 1112-1092 (iii)992 -962 |
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Answer» (i) 1002 – 992 = 100 + 99 = 199 (ii) 1112 - 1092 = 1112 – 1102 + 1102 - 1092 = (111 + 110) + (110 + 109) = 440 (iii) 992 - 962 = 992 – 982 + 982 – 972 + 972 - 962 = (99 + 98) + (98 + 92) + (97 + 96) = 585 |
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| 3939. |
State whether the statements are true (T) or false (F).There is no cube root of a negative integer. |
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Answer» False. Let us take -27 Cube root of -27 i.e. 3√-27 = 3√((-3) × (-3) × (-3)) = -3 |
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| 3940. |
If m is the cube root of n, then n is(a) m3 (b) √m (c) m/3 (d) 3√m |
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Answer» (a) m3 Given in the question, 3√n = m n = m3 |
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| 3941. |
Three numbers are in the ratio 2:3:4. The sum of their cubes is 0.334125. Find the numbers. |
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Answer» Let us assume the three number be 2a, 3a, 4a Then, Given, sum of cube of three numbers is 0.334125 i.e. (2a)3 + (3a)3 + (4a)3 = 0.334125 8a3 + 27a3 + 64a3 = 0.334125 99a3 = 0.334125 a3 = 0.334125/99 a3 = 0.003375 a3 = 3375/1000000 a = 3√(3375/1000000) a = 3√((15 × 15 × 15)/(10 × 10 × 10 × 10 × 10 × 10)) a = 3√(153/106) a = 15/1000 a = 0.015 ∴The numbers are, 2a = 2 × 0.015 = 0.03 3a = 3 × 0.015 = 0.045 4a = 4 × 0.015 = 0.06 |
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| 3942. |
Using distributive law, find the squares of 72. |
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Answer» By using distributive law, We have, 72 = 70 + 2 So, 722 = (70 + 2)2 = (70 + 2) (70 + 2) = 70 (70 + 2) + 2 (70 + 2) = ((70 × 70) + (70 × 2)) + ((2 × 70) + (2 × 2)) = 4900 + 140 + 140 + 4 = 5184 ∴The square of the given number i.e. 722 = 5184 |
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| 3943. |
Evaluate: {(62 + (82)1/2)}3 |
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Answer» Given, {(62 + (82)1/2)}3 = {(36 + (64)1/2)}3 = {(36 + (8)}3 = {44}3 = 44 × 44 × 44 = 85,184 |
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| 3944. |
Which of the following triplets are Pythagorean?(i) (8, 15, 17) (ii) (18, 80, 82) (iii) (14, 48, 51) (iv) (10, 24, 26) (v) (16, 63, 65) (vi) (12, 35, 38) |
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Answer» (i) (8, 15, 17) L.H.S = 82 + 152 = 289 R.H.S = 172 = 289 L.H.S = R.H.S So, it is Pythagoras (ii) (18, 80, 82) L.H.S = 182 + 802 = 6724 R.H.S = 822 = 6724 L.H.S = R.H.S So, it is Pythagoras (iii) (14, 48, 51) L.H.S = 142 + 482 = 2500 R.H.S = 512 = 2601 L.H.S ≠ R.H.S So, it is not Pythagoras (iv) (10, 24, 26) L.H.S = 102 + 242 = 676 R.H.S = 262 = 676 L.H.S = R.H.S So, it is Pythagoras (v) (16, 63, 65) L.H.S = 162 + 632 = 4225 R.H.S = 652 = 4225 L.H.S = R.H.S So, it is Pythagoras (vi) (12, 35, 38) L.H.S = 122 + 352 = 1369 R.H.S = 382 = 1444 L.H.S ≠ R.H.S So, it is Pythagoras |
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| 3945. |
Check whether the given set of three numbers either a Pythagorean triplets or not?(i) 9,12, 15(ii) 7, 11, 13(iii) 10, 24, 26 |
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Answer» (i) (9)2 + (12)2 = 81 + 144 = 225 = (15)2 (ii) (7)2 + (11)2 = 49 + 121 = 170 (iii) (10)2 + (24)2 = 100 + 576 = 676 = (26)2 |
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| 3946. |
State whether the statements are true (T) or false (F).There are five perfect cubes between 1 and 100. |
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Answer» False. There are only 3 perfect cubes between 1 and 100. 2 × 2 × 2 = 8 3 × 3 × 3 = 27 4 × 4 × 4 = 64 |
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| 3947. |
State whether the statements are true (T) or false (F).The cube root of 8000 is 200. |
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Answer» False 3√8000 = 20 |
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| 3948. |
Using distributive law, find the squares of 101. |
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Answer» By using distributive law, We have, 101 = 100 + 1 So, 1012 = (100 + 1)2 = (100 + 1) (100 + 1) = 100 (100 + 1) + 1 (100 + 1) = ((100 × 100) + (100 × 1)) + ((1 × 100) + (1 × 1)) = 10000 + 100 + 100 + 1 = 10201 ∴The square of the given number i.e. 1012 = 10201 |
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| 3949. |
A perfect square number has four digits, none of which is zero. The digits from left to right have values that are: even, even, odd, even. Find the number. |
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Answer» Let us assume PQRS is perfect square, Where, P = even, Q = even, R = odd, S = even So, 8836 is the perfect square. |
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| 3950. |
Fill in the blanks to make the statements true.There are _________ natural numbers between n2 and (n + 1)2. |
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Answer» There are 2n natural numbers between n2 and (n + 1)2. |
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