# Aptitude - Ratio and Proportion - Discussion

Discussion Forum : Ratio and Proportion - General Questions (Q.No. 4)
4.
Seats for Mathematics, Physics and Biology in a school are in the ratio 5 : 7 : 8. There is a proposal to increase these seats by 40%, 50% and 75% respectively. What will be the ratio of increased seats?
2 : 3 : 4
6 : 7 : 8
6 : 8 : 9
None of these
Explanation:

Originally, let the number of seats for Mathematics, Physics and Biology be 5x, 7x and 8x respectively.

Number of increased seats are (140% of 5x), (150% of 7x) and (175% of 8x).

 140 x 5x , 150 x 7x and 175 x 8x 100 100 100

 7x, 21x and 14x. 2

 The required ratio = 7x : 21x : 14x 2

14x : 21x : 28x

2 : 3 : 4.

Discussion:
84 comments Page 2 of 9.

Akash hotty said:   1 year ago
Can anyone explain it shortly?
(8)

Abdulsalam said:   2 years ago
How can we get the total number of seats?

(6)

Pabitra said:   3 years ago
Still not clear.

Can you explain it clearly in a shortcut way?
(1)

Hiitha said:   3 years ago
@All.

Still did not get clarified that why we should use 140/100?
(3)

Insaan said:   3 years ago
@Ram Kundu.

7x : 21x/2 : 14x from 14x : 21x : 28
To make the same denominator we have to multiply with 2 (7x*2/2 and 14*2/2)

14x/2 : 21x/2 : 28x/2 ( now we have the same denominator) we can ignore the denominator
Take LCM of 14x: 21x: 28x,
We get 2x: 3x: 8x.
(5)

Ram Kundu said:   3 years ago
How it become 14x : 21x : 28x? Please explain this step.
(9)

M Zubair said:   3 years ago
Excellent. Thanks all.
(2)

Shaik Babu said:   4 years ago
5 it is increased by 40%=5 * 40/100 = 2.
7 it is increased by50%=7 * 50/100 = 7/2.
8it is increased by 75%=8 * 75/100 = 6.
5+2=7/2+7 = 6 + 8.
7=21/2 = 14.
14=21 = 28.
2=3 = 4.
(60)

Udit said:   4 years ago
How 7x:21/2x:14x =14x:21x:28x?