# Ratio and Proportion aptitude questions

6. The ratio of the number of boys and girls in a college is 7 : 8. If the percentage increase in the number of boys and girls be 20% and 10% respectively, what will be the new ratio?
 A. 8 : 9 B. 17 : 18 C. 21 : 22 D. Cannot be determined

Explanation:

Originally, let the number of boys and girls in the college be 7x and 8x respectively.

Their increased number is (120% of 7x) and (110% of 8x).

 120 x 7x and 110 x 8x 100 100

 42x and 44x 5 5

 The required ratio = 42x : 44x = 21 : 22. 5 5

7. Salaries of Ravi and Sumit are in the ratio 2 : 3. If the salary of each is increased by Rs. 4000, the new ratio becomes 40 : 57. What is Sumit’s salary?
 A. Rs. 17,000 B. Rs. 20,000 C. Rs. 25,500 D. Rs. 38,000

Explanation:

Let the original salaries of Ravi and Sumit be Rs. 2x and Rs. 3x respectively.

 Then, 2x + 4000 = 40 3x + 4000 57

57(2x + 4000) = 40(3x + 4000)

6x = 68,000

3x = 34,000

Sumit’s present salary = (3x + 4000) = Rs.(34000 + 4000) = Rs. 38,000.

8. If 0.75 : x :: 5 : 8, then x is equal to:
 A. 1.12 B. 1.2 C. 1.25 D. 1.3

Explanation:

 (x x 5) = (0.75 x 8)    x = 6 = 1.20 5

9. The sum of three numbers is 98. If the ratio of the first to second is 2 :3 and that of the second to the third is 5 : 8, then the second number is:
 A. 20 B. 30 C. 48 D. 58

Explanation:

Let the three parts be A, B, C. Then,

 A : B = 2 : 3 and B : C = 5 : 8 = 5 x 3 : 8 x 3 = 3 : 24 5 5 5

 A : B : C = 2 : 3 : 24 = 10 : 15 : 24 5

 B = 98 x 15 = 30. 49

10. If Rs. 782 be divided into three parts, proportional to : : , then the first part is:
 A. Rs. 182 B. Rs. 190 C. Rs. 196 D. Rs. 204