Find the ratio and proportion in these sums

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.

If a³ b³ : a³ – b³ = 185 : 158 then a : b =?

a) 7 : 3 b) 2 : 3 c) 10 : 2 d) 5 : 4
Ans: a
Solution: 158a³ 158 b³ = 185a³ – 185b³
185a³ – 158a³ = 158b³ 185b³

27a³ = 343b³
a³/b³ = 343/27

a/b = 3√343/27
a/b = 7/3 = 7 : 3

Two numbers are 40% and 60% more than the third number respectively. What is the ratio of the first number to the second number?

a) 5 : 6 b) 6 : 7 c) 7 : 8 d) 8 : 9
Ans: c

Solution: Let the third number = 100
The first number = 140

and second number = 160
140 : 160

= 7 : 8
If 1/3 of A = 3/4 of B = 1/6 of C, then find the ratio of A : B : C.
a) 18 : 4 : 9 b) 9 : 18 : 4 c) 9 : 4 : 18 d) 18 : 9 : 4
Ans: c
Solution: A/3 = 3B/4 = C/6
A/9 = B/4 = C/18

A : B : C = 9 : 4 : 18
The product of three numbers is 10290. The numbers are in ratio 3 : 5 : 2 . Find the largest number among the three numbers.
a) 30 b) 35 c) 40 d) 45
Ans: b
Solution: 3x × 5x × 2x = 10290
x³ = 10290 / 3 × 5 × 2
x³ = 343
x = 7
The largest number = 5 × 7
= 35
If 25, 35 and P are in consecutive ratio, find the value of P.
a) 49 b) 64 c) 81 d) 100
Ans: a
Solution: 25 : 35 = 35 : P
P = 35 × 35 / 25
P = 49

What will be the third proportional of 16 and 40?
a) 100 b) 120 c) 140 d) 150

Ans: a

Solution: 16 : 40 = 40 : x

x = 40 × 40 /16

x = 100
To be continued…
M. Venkat
Director

MVK Publications
Dilsukhnagar
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