# RRB NTPC Ratio and Proportion Previous Questions

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2020

## RRB NTPC Ratio and Proportion Previous Questions

Download RRB NTPC Top-10 Ratio and Proportion Questions PDF. Questions based on asked questions in previous exam papers very important for the Railway NTPC exam.

Question 1: The ratio of the present age of a man and his wife is 4:3 and 4 years hence the ratio of their ages will be 9:7 If the ratio of their ages at the time of their marriage was 13:9, how many years ago were they married ?

a) 4

b) 8

c) 6

d) 9

Question 2: The volumes of three kinds of materials are in the ratio 3:4:7 and the weights of equal volumes of the three materials are in the ratio 5:2:6 If they are mixed to form a material of 65 kg then the weight of the 2nd material in the mixture is

a) 8 kg

b) 23 kg

c) 15 kg

d) 42 kg

Question 3: 6 : 1 is the ratio of the age of Amar and that of Ajay. After 7 years, this ratio becomes 7 : 2. What is the present age of Ajay ?

a) 9 years

b) 7 years

c) 5 years

d) 11 years

Question 4: If the ratio of boys to girls in a class is 5:3, then which of the following CANNOT be the number of children in that class ?

a) 40

b) 96

c) 150

d) 24

Question 5: A and B got Rs. 4,000 each as their share and C. Rs. 2,000. The ratio in which C, B and A distributed the amount is ?

a) 2 : 2 : 1

b) 2 : 1 : 2

c) 1 : 2 : 2

d) 1 : 4 : 4

Question 6: Find the fourth proportional to 3.6, 6.9 and 11.4.

a) 20.3

b) 18.9

c) 19.6

d) 21.9

Question 7: If 22, x, 88 are in a continued proportion, find the value of x.

a) 22

b) 33

c) 44

d) 36

Question 8: Its. 3,105 is due to be divided among K, L and M in the proportion of 2/3 : 3/4 : 1/2 respectively. How much will L get?

a) Rs. 1,080

b) Rs. 810

c) Rs. 1,215

d) Rs. 970

Question 9: What is the $4^{th}$ proportional of 3, 8, 12, ?

a) 36

b) 26

c) 32

d) 16

Question 10: The mean proportional between 0.16 and 0.64 is:

a) 0.32

b) 0.40

c) 0.27

d) 0.48

Let the ages today be 4x and 3x. Ages four years from now are 4x + 4 and 3x + 4

But 4x+4:3x+4 = 9:7

So, x = 8

So, their current ages = 32 and 24

Let them be married for x years

Age at marriage = 32 – x and 24 – x

But 32 – x : 24 – x = 13: 9

So  x = 6 years.

Let the volumes of the 3 be: 3v, 4v and 7v

Densities of the three are 5d, 2d and 6d

So, the weights are 15dv + 8 dv + 42 dv = 65 dv

But that is 65 kilograms.

The second one’s weight is 8 dv = 8 kgs

Lets Amar and Ajay’s ages be 6x and x. After 7 years, their ages are 6x + 7 and x + 7.

But that 6x+7: x+7 = 7 : 2

So, x = 7

To make a meaningful number of boys and girls (whole numbers), the total number of children should be divisible by 8.

C : B : A = 2000 : 4000 : 4000 = 1 : 2 : 2

product of means = product of extremes

$6.9\times 11.4= 3.6\times ?$

? = 21.85 = 21.9

Given, Ratio = $\dfrac{2}{3} : \dfrac{3}{4} : \dfrac{1}{2}$
LCM = 12
$=\dfrac{2}{3}\times12 : \dfrac{3}{4}\times12 : \dfrac{1}{2}\times12$
$=8:9:6$
Ratio of K, L and M = 8 : 9 : 6

Share of L = $\dfrac{9}{23}\times\ 3105=1215$.

Let the fourth proportion will be x

Then, 3 : 8 :: 12 : x

$3\times\ x=12\times\ 8$

x = 32

So, fourth proportion will be 32.

= $\sqrt{0.16 \times 0.64}$
= $\sqrt{0.1024}$ = 0.32