Get ratio problems right

Here are some practice questions along with solutions that will help you in your preparation for the State government recruitment tests.

Hyderabad: This article is in continuation to the last article focusing on the ratio and proportion topic. Here are some practice questions along with solutions that will help you in your preparation for the State government recruitment tests.

1. If there is a reduction in the number of workers in a factory in the ratio 15 : 11 and an increment in their wage in the ratio 22 : 25, then the ratio by which the total wage of the workers should be decreased is
a) 6 : 5 b) 5 : 6 c) 3 : 7 d) 3 : 5

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Ans: a

Solution: Tricky Approach

Required ratio

= 15 × 22 : 11 × 25 = 6 : 5

2. The total number of students in a school was 660. The ratio between boys and girls was 13 : 9. After some days, 30 girls joined the school and some boys left the school and new ratio between boys and girls became 6 : 5. The number of boys who left the school is?

a) 30 b) 20 c) 50 d) 40
Ans: a
Solution: In the first case,
Boys = 660 × 13/22 = 390
Girls = 660 × 9/22 = 270

If x boys leave the school, then

(390 – x) / (270 30) = 6/5

=>; 390 – x = 360
=>; x = 390 – 360 = 30
3. Two numbers are in the ratio of 3 : 5. If 9 be subtracted from each, then they are in the ratio of 12 : 23. Find the numbers.
a) 28, 95 b) 24, 108 c) 45, 69 d) 33, 55
Ans: d
Solution: According to the question, (Numbers = 3x and 5x)
=>; 69x – 207 = 60x – 108

=>; 9x = 207 – 108 = 99

=>; x = 11

 Required numbers =>; 3 × 11

= 33 and 5 × 11 = 55

4. Veer got twice as many marks in English as in Science. His total marks in English, Science and Maths are 180. If the ratio of his marks in English and Maths is 2 : 3, what is his marks in Science?

a) 50 b) 40 c) 30 d) 80

Ans: c

Solution: Marks in English = 2x

Marks in Maths = 3x
Marks in Science = x

 x 2x 3x = 180

6x = 180 Þ x = 30

5. Three numbers are in the ratio 1 : 2 : 3. By adding 5 to each of them, the new numbers are in the ratio 2 : 3 : 4. The numbers are:

a) 30, 40, 50 b) 5, 10, 15 c) 3, 5, 7 d) 45, 60, 75
Ans: b
Solution: Numbers = x,
2x and 3x
=>; 4x 10

= 3x 15

=>; x = 5

Numbers = 5, 10 and 15

To be continued…

M Venkat
Director

MVK Publications

Dilsukhnagar

7671002120