Aptitude - Ratio and Proportion

Exercise : Ratio and Proportion - General 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?
8 : 9
17 : 18
21 : 22
Cannot be determined
Answer: Option
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?
Rs. 17,000
Rs. 20,000
Rs. 25,500
Rs. 38,000
Answer: Option
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:
1.12
1.2
1.25
1.30
Answer: Option
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:
20
30
48
58
Answer: Option
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:
Rs. 182
Rs. 190
Rs. 196
Rs. 204
Answer: Option
Explanation:

Given ratio = : : = 6 : 8 : 9.

1st part = Rs. 782 x 6 = Rs. 204
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