# Ratios and Proportions – Quiz 7

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# Ratios and Proportions – Quiz 7

### Introduction

Ratios and Proportions is one of important topic in Quantitative Aptitude Section. In Ratios and Proportions – Quiz 7 article candidates can find questions with an answer. By solving this questions candidates can improve and maintain, speed, and accuracy in the exams. Ratios and Proportions – Quiz 7 questions are very useful for different exams such as IBPS PO, Clerk, SSC CGL, SBI PO, NIACL Assistant, NICL AO, IBPS SO, RRB, Railways, Civil Services etc.

### Q1

If a:b = 3:4, b:c = 7:9, c:d = 5:7, find a:d?
A. 5:12 B. 7:12 C. 3:11 D. 5:11

A
$\frac {a}{d} = \frac {3}{4} \times \frac {7}{9} \times \frac {5}{7} \rightarrow \frac {5}{12}$

### Q2

The proportion of copper and zinc in the brass is 13:7. How much zinc will there be in 100 kg of brass?
A. 20 kg B. 35 kg C. 55 kg D. 14 kg

B
$\frac {7}{20} \times 100 = 35$

### Q3

The ratio of two numbers is 2:3 and the sum of their cubes is 945. The difference of number is?
A. 3 B. 4 C. 5 D. 6

A
2x, 3x
8x cube + 27x cube = 945
35x cube = 945
x cube = 27 $\rightarrow$ x = 3

### Q4

The ratio of the number of ladies to gents at a party was 1:2 but when 2 ladies and 2 gents left, the ratio became 1:3. How many people were at the party originally?
A. 36 B. 24 C. 12 D. 6

C
x, 2x
(x-2):(2x-2) = 1:3
3x - 6 = 2x-2
x = 4
x + 2x = 3x
$\rightarrow$ 3 $\times$ 4 = 12

### Q5

The first three terms of a proportion are 3, 9 and 12. The fourth term is?
A. 4 B. 6 C. 18 D. 36

D
$\frac {9 \times 12}{3} = 36$