Explore topic-wise InterviewSolutions in .

Right OPTION is (d) two ten rupees and one FIVE rupees

Explanation: If the boy SELECTS two ten rupees and one five rupees coins then he’ll get the MAXIMUM amount. While in any other combination the amount WOULD be less.

Correct option is (d) RAJ’s AGE is 40 YEARS and Anu’s age is 32 years

The explanation: Let the present ages of Anu and Raj be 4x years and 5x years respectively.

After eight years. Anu’s age = (4x + 8) years;

After eight years, Raj’s age = (5x + 8) years.

∴ the ratio of their ages after eight years = \(\frac{4x+8}{5x+8}\)

This is given to be 5:6.

∴ \(\frac{4x+8}{5x+8} = \frac{5}{6}\)

∴ 6(4x+8)=5(5x+8)

∴ 24x+48=25x+40

∴ –x=-8

∴ x=8

∴ Anu’s age = 4×8 = 32years

∴ Raj’s age = 5×8 = 40years.

Correct answer is (a) \(\frac{3}{4}\)

Explanation: LET the COMMON ratio be x. The age of two brothers after five years would be (2x+5) years and (3x+5)years.

Therefore (2x+5)+(3x+5)=30

Therefore 2x+5+3x+5=30

Therefore 5x=20

Therefore x=4

Therefore the brothers age would be 10 years and 15 years respectively.

Now, after five years their ages would be 15 years and 20 years respectively.

The ratio of the brothers ages = \(\frac{15}{20} = \frac{3}{4}\).

Correct answer is (a) 3 notes

Explanation: If a notebook costs THIRTY rupees and one has ten rupees notes. Let the number of ten rupees NOTE required be x.

∴ 10x=30

∴ x=\(\frac{30}{10}\)

∴ x=3.

Right option is (B) 23 rupees

For EXPLANATION: Let the amount received by the girl from the shopkeeper be x rupees.

∴ 27+x=50

∴ x=50-27

∴ x=23.

The correct option is (a) 56 years

To explain: The PRESENT age of Rahul and Rajiv is 27 and 19 respectively, after five years their age will be Rahul’s age =(27+5)years and Rajiv’s age = (19+5)years.

Sum of Rahul’s age and Rajiv’s age = (27+5)+(19+5)

∴ Sum of Rahul’s age and Rajiv’s age = 32+24

∴ Sum of Rahul’s age and Rajiv’s age = 56 years.

The CORRECT answer is (c) 1800 rupees

Best explanation: MOHAN has to PAY TWO hundred rupees. He has two THOUSAND rupees with him. Let amount he gets back be x rupees.

∴ 2000-x=200

∴ 2000-200=x

∴ x=1800 rupees.

The correct option is (c) 28 years

For explanation I WOULD say: LET Sara’s age be x years. ∴ MARRY’s age is 2x years.

Now after five years Sara’s age= (x+5)years and Marry’s age = (2x+5)years

We know that, (x+5)+(2x+5)=52

∴ x+5+2x+5=52

∴ 3x+10=52

∴ 3x=42

∴ x=14 years

∴ Sara’s present age is 14 years. As we know that, Marry’s age is twice that of Sara’s age

∴ Marry’s age 28 years.

The CORRECT answer is (a) 2x+1=0

The best explanation: 13x-2=21x+2

∴ 13x-21x=2+2

∴ -8x=4

∴ x=\(\FRAC{-1}{2}\).

Right choice is (a) x=0

The best I can EXPLAIN: \(\frac{12X}{2} + \frac{6x}{5}\) = 0

∴ \(\frac{5*12x}{2*5} + \frac{2*6x}{5*2)}\) = 0

∴ 60x+12x=0

∴ 72x=0

∴ x=0.

The CORRECT option is (a) 10X = 5

Easiest explanation: \(\frac{2x+1}{2} + \frac{2x-1}{3}\) = 1

∴ \(\frac{3*(2x+1)+2*(2x-1)}{6}\) = 1

∴ \(\frac{6x+3+4x-2}{6}\) = 1

∴ 6x + 3 + 4x – 2 = 6

∴ 10x + 1 = 6

∴ 10x = 5

Right CHOICE is (b) \(\frac{27}{273}\)

The BEST explanation: \(\frac{3x+7}{12} + \frac{22x-1}{3}\) = 1

∴ \(\frac{3*(3x+7)+12*(22x-1)}{12*3}\) = 1

∴ 9x + 21 + 264x – 12 = 36

∴ 273x + 9 = 36

∴ 273x = 27

∴ x = \(\frac{27}{273} = \frac{9}{91}\).

The CORRECT option is (B) \(\FRAC{7}{2}\)

Explanation: 11x – 2 = 7x + 12

∴ 11x – 7x = 12 + 2

∴ 4x = 14

∴ x = \(\frac{14}{4} = \frac{7}{2}\).

Right ANSWER is (c) \(\FRAC{5}{8}\)

Easy EXPLANATION: \(\frac{14y-12}{12y-14} = \frac{1}{2}\)

∴2 * (14y – 12) = 1 * (12y – 14)

∴28y – 24 = 12y – 14

∴28y – 12y = -14 + 24

∴16y = 10

∴y = \(\frac{10}{16} = \frac{5}{8}\).

The CORRECT choice is (a) \(\frac{3}{2}\)

Best EXPLANATION: 2x – 3 = 0

∴2x = 3

∴x = \(\frac{3}{2}\).

The CORRECT ANSWER is (a) \(\FRAC{-3}{5}\)

To explain I would say: 2Y – 2 = 7y + 1

∴2y – 7y = 1 + 2

∴-5y = 3

∴y = \(\frac{-3}{5}\).

Right choice is (b) \(\FRAC{-22}{5}\)

The BEST explanation: 3N – 13 = 13N +31

∴3n – 13n = 31 + 13

∴-10n = 44

∴n = \(\frac{-44}{10} = \frac{-22}{5}\).

Right ANSWER is (a) \(\frac{2}{3}\)

To EXPLAIN I would say: 0.25(12t – 4) = 1

∴3t – 1 = 1

∴3t = 2

∴t = \(\frac{2}{3}\).

Right choice is (c) \(\frac{59}{7}\)

The explanation is: \(\frac{2v-3}{2} + \frac{3v}{4}\) = 12

∴\(\frac{4*(2v-3)}{4*2} + \frac{2*3v}{4*2}\) = 12

∴\(\frac{8v-12+6v}{8}\) = 12

∴8v – 12 + 6v = 12 * 8

∴14v – 12 = 96

∴14v = 108

∴v = \(\frac{108}{14} = \frac{59}{7}\).

The CORRECT ANSWER is (a) \(\frac{2}{3}\)

The best explanation: \(\frac{m-1}{2} + \frac{2m+3}{3}\) = 2

∴\(\frac{3*(m-1)}{3*2} + \frac{3*(2m+3)}{2*3}\) = 2

∴\(\frac{3m-3+6m+9}{6}\) = 2

∴\(\frac{9m+6}{6}\) = 2

∴9m + 6 = 12

∴9m = 6

∴m = \(\frac{2}{3}\).

Correct OPTION is (c) \(\FRAC{1}{12}\)

For explanation: \(\frac{x}{5} + \frac{x}{7} = \frac{1}{35}\)

∴\(\frac{7*x+5*x}{5*7} = \frac{1}{35}\)

∴\(\frac{7X + 5x}{35} = \frac{1}{35}\)

∴\(\frac{12x}{35} = \frac{1}{35}\)

∴12x = 1

∴x = \(\frac{1}{12}\).

Correct answer is (a) \(\frac{-1}{2}\)

EXPLANATION: 3(X – 3) = 5(x + 2)

∴3x – 9 = 5x + 10

∴3x – 5x = 10 – 9

∴-2x = 1

∴x = \(\frac{-1}{2}\).

Right answer is (a) x = \(\frac{147}{16}\)

EASY EXPLANATION: \(\frac{2x-11}{2} + \frac{x}{7}\) = 5

∴\(\frac{7*(2x-11)}{7*2} + \frac{2*x}{2*7}\) = 5

∴\(\frac{14x-77+2x}{14}\) = 5

∴16x – 77 = 5 * 14

∴16x – 77 = 70

∴16x = 147

∴x = \(\frac{147}{16}\).

Right option is (d) 8 cm

The BEST explanation: Perimeter of a SCALENE triangle = Length of side 1 + Length of side 2 + Length of side 3

∴ 23 = 12 + 3 + Length of side 3

∴ 23 = 15 + Length of side 3

∴ Length of side 3 = 8 cm.

The CORRECT CHOICE is (a) 16

Explanation: Let RAM’s present AGE be X years.

∴ Shyam’s present age will be 2x years.

After 10 years Shyam’s age would be, (2x + 10) years.

∴ Shyam’s age after 10 years = 2 * 3 + 10

∴ Shyam’s age after 10 years = 6 + 10

∴ Shyam’s age after 10 years = 16 years.

Right answer is (b) 12x

The best explanation: If a SET is formed CONSISTING all the multiples of 12 it would be LIKE [12,24,36,48,60,…..]

The set of multiples of 12 is formed by multiplying the set of NATURAL numbers with 12.

Let the set of natural number be represented by x

∴ the general equation of multiples of 12 = 12x

Correct choice is (a) \(\frac{23}{3}\)

The explanation: Let the number chosen by Arya be x.

The FIRST operation CARRIED out by Arya was adding \(\frac{13}{3}\) to the number.

Hence, the equation formed is x + \(\frac{13}{3}\) = 12

The second operation is to DIVIDE throughout by 3.

Hence, the equation is modified to \(\frac{x}{3} + \frac{13}{9}\) = 4

\(\frac{x}{3} + \frac{13}{9}\) = 4

∴ \(\frac{3X}{9} + \frac{13}{9} = \frac{36}{9}\)

∴ 3x + 13 = 36

∴ 3x = 23

∴ x = \(\frac{23}{3}\).

The correct option is (a) 200

Easiest explanation: LET the NUMBER of coins required be X.

The amount to be paid is rupees 400.

(2 * x) = 400

∴ 2x = 400

∴ x = 200

Raj needs 200 coins each of two rupees in order to PAY the bill amount.

The correct choice is (a) 5

The explanation: LET the number subtracted be x.

484 – x = 459

∴ 484 – 459 = x

∴ x = 25

∴ the subtracted number is 25 and 25 is square of number 5.

The correct ANSWER is (b) Kavya’s age = 5 YEARS; Jon’s age = 15 years

To elaborate: Let us CONSIDER Kavya’s age as x years.

Then Jon’s age would be 3x years.

Kavya’s age five years ago was (x – 5) years.

Jon’s age five years ago was (3x – 5) years.

It is given that Jon’s age five years ago was two times Kavya’s age.

Thus, (3x – 5) = 2 * (x – 5)

Or 3x -5 = 2x – 10

Or x = 5

∴ Jon’s age = 3x

∴ Jon’s age = 3 * 5

∴ Jon’s age = 15 years

∴ Kavya’s age = x

∴ Kavya’s age = 5 years.

Correct answer is (b) 71

Easy explanation: The highest scorer scores 2 marks less then MAXIMUM achievable SCORE.

Score of highest scorer = Maximum achievable score – 2

∴ Score of highest scorer = 100 -2

∴ Score of highest scorer = 98

Now, Raj’s score can be calculated by,

Raj’s score= Score of highest scorer – 27

∴ Raj’s score = 98 – 27

∴ Raj’s score = 71.

Correct choice is (C) -24 and -28

The EXPLANATION is: Let the common MULTIPLE be x. We know that the INTEGERS sum up to -52.

6x + 7x = -52

∴ 13x = -52

∴ x = -4

Since, x = -4 the integers are -24 and -28.

The correct choice is (a) 529, 552, 575

For explanation I WOULD SAY: LET (x – 23), x and (x + 23) be the three consecutive multiples. Now, the sum of these numbers is 1656.

(x – 23) + x + (x + 23) = 1656

∴ x – 23 + x + x + 23 = 1656

∴ 3x = 1656

∴ x = 552

Hence, x – 23 = 529 and x + 23 = 575

The three consecutive multiples of 23 which sum up to 1656 are 529, 552 and 575.

The correct answer is (B) 7 m

The explanation: The FORMULA for PERIMETER of a square is 4 × (side)

Perimeter = 4 × (side)

∴ 28 = 4 × (side)

∴ side = 7

Hence, the length of the side of the square is 7 m.

The correct choice is (a) 2 and 3

Easy explanation: Let the COMMON MULTIPLE be X.

∴ 2x + 3x = 5

∴ 5X = 5

∴ x = 1

Since, x = 1 the natural numbers are 2 and 3.

The correct answer is (a) 262, 263 and 264

To explain I would SAY: Let the first number be x. Since they are consecutive numbers the next number would be (x + 1) and the third number would be (x + 2). Now as the SUM of the numbers is given as 789 we solve the equation by ADDING the three consecutive variables.

x + (x + 1) + (x + 2) = 789

∴ 3x + 3 = 789

∴ 3x = 789 – 3

∴ 3x = 786

∴ x = 262

Hence the three consecutive numbers are 262, 263 and 264.

Correct option is (b) 15 two-rupee and 5 five-rupee

To explain I would SAY: Let the number of five-rupee coins with Bansal be x. Then the number of two-rupee coins will be 7X. The amount from

(i) Five-rupee coins = 5x

(ii) Two-rupee coins = 2x × 7 = 14x

Hence the total amount with Bansal is 19x.

∴ 19x = 95

∴ x = 5

Thus, the number of five-rupee COIN = 5

and number of two-rupees coin = 15.

Right answer is (b) 3 CM

To explain I WOULD say: For any rectangle the formula for perimeter is 2 × (Length + Breadth). Here we already KNOW the breadth of the rectangle. When we substitute the known VALUES in the formula for perimeter of a rectangle we get,

12 = 2 × (Length + 2)

∴ 6 = Length + 2

∴ Length = 4 cm.