Crucial 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 on the ratio and proportion topic that will help you in your preparation for the State government recruitment jobs.

The ratio of marks obtained by a student in three subjects is 1 : 2 : 3. The school has decided to 5% grace marks for each subject. Find the student’s new ratio.
a) 1 : 2 : 3 b) 2 : 3 : 4 c) 5 : 7 : 8 d) 3 : 2 : 1
Ans: a
Solution: 1 × 105% : 2 × 105% : 3 × 105%
1 : 2 : 3

The sub-duplicate ratio of 121 : 169

a) 14,641 : 28,561 b) 11 : 13

c) 28,561 : 14,641 d) 13 : 11

Ans: b

Solution: Sub-duplicate ratio of a : b =

=

= 11 : 13

Out of 120 applications for a post, 70 are males and 80 have a driver’s licence. What is the ratio between the minimum to maximum number of males having driver’s licence?

a) 1 : 7 b) 2 : 7 c) 3 : 7 d) 4 : 7

Ans: c

Solution: 120 (Total applicants)

Males Females

70 50

NOTE: For the minimum number of males to have a driver’s license all 50 female have a driver’s licence.

For the maximum number of males to have driver’s license all 70 males have a driver’s licence.

80 (Driver’s licence)

Males Males

(Minimum) (Maximum)

30 70

30 : 70

3 : 7

If a : b = b : c, then a4 : b4 is equal to

a) c² : a² b) a² : c² c) ac : b² d) b² : ac

Ans: b

Solution: a : b = b : c

b² = ac

a4 : b4
a4 : (ac)²

a² : c²
If (a c) : (b c) : (c a) = 7 : 8 : 9, then find a : b : c

a) 3 : 4 : 5 b) 4 : 3 : 5 c) 5 : 4 : 3 d) 3 : 5 : 4

Ans: b

Solution: (a b) (b c) (c a) = 7 8 9

2(a b c) = 24

(a b c) = 12

a = (a b c) – (b c)

= 12 – 8

= 4

b = (a b c) – (c a)

= 12 – 9
= 3
c = (a b c) – (a b)
= 12 – 7
= 5
a : b : c = 4 : 3 : 5
To be continued…
M.Venkat
Director

MVK Publications

Dilsukhnagar

7671002120