Sample questions for ratio and proportion

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 jobs.
1. The ratio of 25 2.5 : 5³ is same as

a) 1 : 25 b) 25 : 1 c) 5 : 6 d) 6 : 5

Ans: b

Solution: 25 2.5/ 5³ = 5 2 (2.5)/ 5³

5 5/5³
5 2/ 1

= 25 : 1

2. If ( a b) : ab = 4 : 1 , where a >; b >; 0 then a : b is
a) (2 3):(2- 3) b) (3 2):(3- 2)
c) (2- 3):(2 3) d) (3- 2):(3 2)
Ans: a
Solution: (a b)/ ab = 4/1
(a b)2/( ab)2 = 4 2/ 1 2

(a² b² 2ab)/ab = 16/1
a² b² 2ab – 4ab = 12ab

(a – b)² = 2ab
(a b)/2( ab) = 4/1

(a b)/2( ab) = 2/1
By componendo and dividendo,

a b 2( ab) / a b – 2( ab) = 2 1/1-1
a b / a – b = 3/1

Again using componendo and dividend rule,
2 a/2 b = 3 1/ 3-1
a/ b = 3 1/ 3-1

On squaring on both sides

a/b = 3 1 2 3/ 3 1-2 3

4 2 3/ 4-2 3
= 2 3/ 2- 3

a : b = 2 3:2- 3
3. If a : b = c : d = e : f = 1 : 2, then (3a 5c 7e) : (3b 5d 7f) is equal to
a) 1 : 2 b) 2 : 1 c) 1 : 4 d) 4 : 1
Ans: a
Solution: a/b = c/d = e/f = 1/2
3a/3b = 5c/5d = 7e/7f = 1/2

3a 5c 7e /3b 5d 7f = 1/2
4. If a/b = b/c = c/d = d/e = 2/3 , then find the value of (a b c d e)/(b c d e f)

a) 2/3 b) 3/2 c) 1 d) 4/9

Ans: a

Solution: We know that a/b = c/d = e/f……… = (a c e)/(b d f)

5. If a and b are rational numbers and a b 3 = 1/2 3, then a : b

a) 1 : 2 b) 2 : 1 c) – 3 : 1 d) 1: 3
Ans: b
Solution: a b 3 = 1/2- 3 × 2 3/2 3
a b 3 = 2 3
a = 2 , b = 1
a : b = 2 : 1
To be continued…
M.Venkat
Director

MVK Publications

Dilsukhnagar

7671002120