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
Answer: Option
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 9 of 9.

Jaya Prakash said:   6 months ago
@All.

Here 5:7:8 is not the original no of seats.

So, Initially, we assume the no of seats as 100% for each. so each is increased to 140%, 150%, and 175% respectively.

To know how many seats are required we are multiplying 140% * 5.
(7)

Nayana said:   6 months ago
700 : 1050 : 1400.

How its comes?
(1)

Sri said:   4 months ago
To find the increased seats, we multiply the original seats by (1 + \frac{{40}}{{100}}).
(2)

Freeze said:   2 months ago
5 it is increased by 40% = 5 * 40/100 = 2.
7 it is increased by 50% = 7 * 50/100 = 7/2.
8 it is increased by 75% = 8 * 75/100 = 6.
We need to add the ratios with their increased values.
(5) +2 : (7) +7/2 : (6) + 8.
7 : 21/2 : 14.

Multiply 2 on all sides.
14: 21: 28.
Divide 7 on all sides.
2: 3 : 4.
(9)


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