71 + Interview Questions in Linear Equations In One Variable in Mathematics

51.	At present Disha’s mother is three times the age of Disha. After 5 years their ages will sum up to 70 years. Find the present age.(a) Disha 10 and her mother 30(b) Disha 12 and her mother 36(c) Disha 13 and her mother 39(d) Disha 15 and her mother 45This question was posed to me during an interview.This interesting question is from Solving Linear Equations with Variables on Both the Sides topic in division Linear Equations in One Variable of Mathematics – Class 8
Answer» Right ANSWER is (d) Disha 15 and her MOTHER 45 Best explanation: Let Disha’s age be x years then her mother would be 3x years old. After 5 years, their ages are x + 5 (Disha) and 3x + 5 (Disha’s Mother) respectively. (x + 5) + (3x + 5) = 70 ∴ x + 5 + 3x + 5 = 70 ∴ 4x + 10 = 70 ∴ 4x = 60 ∴ x = 15 Since x = 15 we KNOW that Disha’s present age is 15 years, to find her mother’s age we have (3×15) i.e. 45 years.

Discussion

52.	The process of shifting any constant or variable in an equation from one side to other is ___________(a) assosiativity(b) distributivity(c) commutativity(d) transpositionThe question was posed to me in a national level competition.The above asked question is from Applications of Linear Equation (Just Solving the Equations) topic in chapter Linear Equations in One Variable of Mathematics – Class 8
Answer» Right answer is (d) transposition To explain I would SAY: This is the property used while we solve equations. In this property when we TAKE a component of equation from LHS to RHS or VICE versa the signs change, the change of signs is in order to BALANCE the equation.

Discussion

53.	If Malik has 3 coins and his sister has 4 coins each of 2 rupees, what will be the sum of amount both have?(a) 14 rupees(b) 13 rupees(c) 12 rupees(d) 7 rupeesThe question was posed to me by my college director while I was bunking the class.The above asked question is from Solving Linear Equations with Variables on Both the Sides topic in division Linear Equations in One Variable of Mathematics – Class 8
Answer» The correct CHOICE is (a) 14 RUPEES Explanation: There are 7 COINS in total. When we multiply 2 × 7 we get 14. Hence, the total amount with them is 14 rupees.

Discussion

54.	The degree of linear equation in one variable is _______(a) 1(b) 2(c) 3(d) 4The question was posed to me in quiz.This interesting question is from Applications of Linear Equation (Just Solving the Equations) topic in chapter Linear Equations in One Variable of Mathematics – Class 8
Answer» CORRECT CHOICE is (a) 1 For explanation I WOULD SAY: Degree is the highest power of any EQUATION. In any linear equation the highest power is 1 Hence the degree of linear equation in one variable is 1.

Discussion

55.	If a side of a regular hexagon is 20 cm then what will be the perimeter of that regular hexagon?(a) 120 cm(b) 120 m(c) 60 cm(d) 60 mThis question was posed to me during an online interview.This question is from Applications of Linear Equation (Just Solving the Equations) topic in portion Linear Equations in One Variable of Mathematics – Class 8
Answer» Correct choice is (a) 120 cm Explanation: A regular HEXAGON has SIX equal sides. PERIMETER of a regular hexagon = 6 × (Side of the hexagon) Perimeter of a regular hexagon = 6 × (20) Perimeter of a regular hexagon = 120 cm.

Discussion

56.	If circumference of a circle is 6.28 cm then what is the radius of the circle?(a) 2 cm(b) 1 cm(c) 4 cm(d) 3 cmThis question was addressed to me in a national level competition.I want to ask this question from Applications of Linear Equation (Just Solving the Equations) in division Linear Equations in One Variable of Mathematics – Class 8
Answer» Correct answer is (B) 1 cm The explanation is: CIRCUMFERENCE of a CIRCLE = 2 × π × Radius 6.28 = 2 × 3.14 × Radius Radius = 1.

Discussion

57.	There are two parties in an election the ratio of their votes is 2:3. The total number of voters who took part in that election are 1200. How many votes did the winning party get?(a) 480(b) 600(c) 1200(d) 720This question was addressed to me in an international level competition.I'd like to ask this question from Applications of Linear Equation (Just Solving the Equations) in section Linear Equations in One Variable of Mathematics – Class 8
Answer» Right option is (d) 720 For explanation I would say: LET the COMMON ratio be x. ∴ 2x + 3x = 1200 ∴ 5x = 1200 ∴ x = 240 The party which gets higher number of VOTES wins the election so, the party which has 3x votes is the winning party. Number of votes = 3x = 3 × 240 = 720.

Discussion

58.	Sum of two distinct numbers is positive then which of the following statements is correct?(a) Both numbers are equal and negative(b) Greater one positive and smaller one negative(c) Both positive(d) Both negativeI have been asked this question during an interview.I need to ask this question from Applications of Linear Equation (Just Solving the Equations) topic in division Linear Equations in One Variable of Mathematics – Class 8
Answer» Right CHOICE is (d) Both negative The best explanation: Here we are GIVEN that there are two DISTINCT numbers, so the option stating equal and negative is ruled out. The SECOND information we have is the sum is negative, so if the greater number is positive than the sum is positive and hence the option which states greater one positive and smaller one negative also is ruled out. Now we have two options left they are both positive or negative. We know that sum two positive number is positive. So the option left is both negative which is the CORRECT options.

Discussion

59.	At Tanay’s birth, he was 34 years younger than his father. What will be his age after 20 years?(a) 20(b) 54(c) 0(d) 14I got this question in final exam.The query is from Applications of Linear Equation (Just Solving the Equations) topic in chapter Linear Equations in One Variable of Mathematics – Class 8
Answer» RIGHT OPTION is (a) 20 Best explanation: At birth Tanay’s AGE would be 0, at that TIME difference in ages was 34 years. As the time PASSES Tanay and his father’s age increases but the difference remains same. Hence, Tanay’s age would be i.e. Age at his birth + 20 years i.e. 0 + 20 years i.e. 20 years.

Discussion

60.	Perimeter of a square is 48 m. What is the length of one side?(a) 12 m(b) 192 m(c) 13 m(d) 14 mThis question was addressed to me in an interview.My doubt stems from Applications of Linear Equation (Just Solving the Equations) in division Linear Equations in One Variable of Mathematics – Class 8
Answer» Correct answer is (a) 12 m Explanation: Formula for perimeter is SQUARE, Perimeter = 4 × (Length of one SIDE) 48 = 4 × (Length of one side)13 Dividing throughout by 4 we get, Length of one side = 12.

Discussion

61.	What is the solution of the equation, 7 + 2x = 0?(a) \(\frac{2}{7}\)(b) \(\frac{-2}{7}\)(c) \(\frac{7}{2}\)(d) \(\frac{-7}{2}\)This question was addressed to me in examination.Question is from Solving Linear Equations with Variables on One Side and Number on the Other in section Linear Equations in One Variable of Mathematics – Class 8
Answer» CORRECT choice is (d) \(\FRAC{-7}{2}\) EASY explanation: 7 + 2X = 0 Step 1: TRANSPOSING 7 to RHS we get, 2x = -7 Step 2: Dividing both sides by 2 we get, x = \(\frac{-7}{2}\).

Discussion

62.	What should be added to twice the rational number \(\frac{13}{3}\) to get \(\frac{13}{6}\)?(a) \(\frac{-13}{4}\)(b) \(\frac{-13}{2}\)(c) \(\frac{13}{2}\)(d) \(\frac{13}{4}\)This question was addressed to me by my college director while I was bunking the class.Question is from Applications of Linear Equation (Just Solving the Equations) in chapter Linear Equations in One Variable of Mathematics – Class 8
Answer» Correct CHOICE is (b) \(\frac{-13}{2}\) Best explanation: TWICE the rational number is (2) × \(\frac{13}{3} = \frac{26}{3}\) Let X be added to \(\frac{26}{3}\), x + \(\frac{26}{3} = \frac{13}{6}\) x = \(\frac{13}{6} – \frac{26}{3}\) x = \(\frac{13}{6} – \frac{52}{6}\) x = \(\frac{-39}{6}\) x = \(\frac{-13}{2}\).

Discussion

63.	The solution of equation 3x + 6 = -3 is x = -3.(a) True(b) FalseThis question was posed to me in semester exam.My question is taken from Solving Linear Equations with Variables on One Side and Number on the Other topic in section Linear Equations in One Variable of Mathematics – Class 8
Answer» CORRECT choice is (a) True To explain: 3X + 6 = -3 Step 1: Transposing 6 to RHS we get, 3x = -9 Step 2: Dividing both sides by 3 we get x = -3.

Discussion

64.	Solve: 16 = 3m – 2.(a) m = -5(b) m = 5(c) m = 6(d) m = -6The question was asked during an interview.I'm obligated to ask this question of Solving Linear Equations with Variables on One Side and Number on the Other topic in division Linear Equations in One Variable of Mathematics – Class 8
Answer» Correct OPTION is (c) m = 6 Easiest EXPLANATION: Step 1: Transposing – 2 to LHS we get, 18 = 3m Step 2: DIVIDING both the sides by 3 we get, m = 6.

Discussion

65.	Pick the equation which has the solution in the form of prime number.(a) 2x = 3(b) 3z = -6(c) 4y – 3 = 2(d) 2z – 2 = 2The question was asked during an interview.The above asked question is from Solving Linear Equations with Variables on One Side and Number on the Other in portion Linear Equations in One Variable of Mathematics – Class 8
Answer» Right choice is (d) 2z – 2 = 2 For explanation: A prime number is the number which can be formed by multiplying only TWO NUMBERS which are 1 and the number itself. Solving equation, 2z – 2 = 2 Step 1: Transposing – 2 on RHS we get, 2z = 4 Step 2: Dividing equation by 2 we get, z = 2 Since 2 is GREATER than 0 and can be formed only by multiplying 1 and 2 it is a prime number.

Discussion

66.	Pick the equation from the given one’s which have solution as z = 2.(a) 2z -2 = 3(b) 3z -2 = -2(c) 3z -3 = 3(d) 4z + 3 = 3This question was posed to me in an online quiz.My question is based upon Solving Linear Equations with Variables on One Side and Number on the Other in chapter Linear Equations in One Variable of Mathematics – Class 8
Answer» RIGHT CHOICE is (C) 3z -3 = 3 Explanation: Solving the 3z – 3 = 3 we get, Step 1: Transposing -3 on RHS we get, 3z = 6 Step 2: Dividing both SIDES by 3 we get, z = 2 Hence, this is the solution of our question.

Discussion

67.	Solve: 7x – 2 = 3.(a) x = \(\frac{5}{7}\)(b) x = \(\frac{7}{5}\)(c) x = \(\frac{3}{5}\)(d) x = \(\frac{5}{3}\)The question was posed to me during an interview.I would like to ask this question from Solving Linear Equations with Variables on One Side and Number on the Other topic in chapter Linear Equations in One Variable of Mathematics – Class 8
Answer» Correct option is (a) X = \(\FRAC{5}{7}\) Easy explanation: 7x – 2 = 3 Step 1: TRANSPOSING -2 on RHS we get, 7x = 5 Step 2: Dividing both sides by 7 we get, x = \(\frac{5}{7}\).

Discussion

68.	Solve: \(\frac{5}{2}x + \frac{3}{2} = \frac{6}{4}\).(a) x = 1(b) x = 2(c) x = 3(d) x = 0This question was addressed to me in examination.My question is taken from Solving Linear Equations with Variables on One Side and Number on the Other in section Linear Equations in One Variable of Mathematics – Class 8
Answer» The correct choice is (d) X = 0 For explanation: \(\frac{5}{2}x + \frac{3}{2} = \frac{6}{4}\) Step 1: Reducing the fraction we get, \(\frac{5}{2}x + \frac{3}{2} = \frac{3}{2}\) Step 2: Multiplying LHS and RHS by 2 we get, 5x + 3 = 3 i.e. 5x = 0 Step 3: Dividing both sides by 5 we get, x = 0.

Discussion

69.	In equation 3x + 4 = 10,by transposing the variable on RHS we get ________(a) -4 = 10 – 3x(b) 4 = 3x + 10(c) 4 = -3x + 10(d) -4 = – 3x – 10I had been asked this question in exam.Asked question is from Solving Linear Equations with Variables on One Side and Number on the Other in section Linear Equations in One Variable of Mathematics – Class 8
Answer» The correct answer is (c) 4 = -3X + 10 To explain I would say: While shifting the VARIABLE from LHS to RHS the SIGN changes from positive to negative and vice versa. Here, the given equation is 3x + 4 = 10.

Discussion

70.	Solve equation 7x + 14 = 21 to find value of x.(a) x = 1(b) x =-1(c) x = 2(d) x = -2I got this question in an online interview.I would like to ask this question from Solving Linear Equations with Variables on One Side and Number on the Other topic in portion Linear Equations in One Variable of Mathematics – Class 8
Answer» Right option is (a) x = 1 To explain I would SAY: 7x + 14 = 21 Step 1: Solving the equation, we take constant 14 on the RHS MAKING 7x = 7 Step 2: DIVIDING LHS and RHS with 7 we GET x = 1.

Discussion

71.	Find the solution for the equation 3x + 3 = 4.(a) 3(b) \(\frac{1}{3}\)(c) 4(d) \(\frac{1}{4}\)I have been asked this question in an interview for job.I need to ask this question from Solving Linear Equations with Variables on One Side and Number on the Other in chapter Linear Equations in One Variable of Mathematics – Class 8
Answer» Correct option is (B) \(\FRAC{1}{3}\) To elaborate: 3x + 3 = 4 Step 1: Subtract 3 from both the sides, 3x + 3 – 3 = 4 – 3 3x = 1 Step 2: Divided both the sides by 3, X = \(\frac{1}{3}\) So, we have solution for the equation x = \(\frac{1}{3}\)

Discussion

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The degree of linear equation in one variable is _______(a) 1(b) 2(c) 3(d) 4The question was posed to me in quiz.This interesting question is from Applications of Linear Equation (Just Solving the Equations) topic in chapter Linear Equations in One Variable of Mathematics – Class 8

Perimeter of a square is 48 m. What is the length of one side?(a) 12 m(b) 192 m(c) 13 m(d) 14 mThis question was addressed to me in an interview.My doubt stems from Applications of Linear Equation (Just Solving the Equations) in division Linear Equations in One Variable of Mathematics – Class 8

The solution of equation 3x + 6 = -3 is x = -3.(a) True(b) FalseThis question was posed to me in semester exam.My question is taken from Solving Linear Equations with Variables on One Side and Number on the Other topic in section Linear Equations in One Variable of Mathematics – Class 8

Solve: 16 = 3m – 2.(a) m = -5(b) m = 5(c) m = 6(d) m = -6The question was asked during an interview.I'm obligated to ask this question of Solving Linear Equations with Variables on One Side and Number on the Other topic in division Linear Equations in One Variable of Mathematics – Class 8