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:
74 comments Page 2 of 8.

Priya said:   3 years ago
Nice explanation Mr. Harjinder Singh. Way to think in a simple manner.

Rahul said:   3 years ago
Let the ratio 500:700:800.
Increase 200:350:600.
700:105:1400=14:21:28=2:3:4 answer.

Himanshu said:   3 years ago
5:7:8 means 5/20 which means 0.25.

2:3:4 means 2/9 which means 0.22.

But it is saying that the seats have increased. But according to maths the seats have decreased.

Can anyone please tell me how is this possible?

Subho said:   4 years ago
Math seats 5 increased will be 4% = now number of total seats 7. Physics seats 7 increased will be 50% = now number of total seats = 10.5. Bio seats 8 increased will be 75%= now the total number of state 14.

So, new seats ratio are 7:10.5:14.
= 2:3:4.

Himesh said:   4 years ago
@All.

Would this formula be applicable if the number of seats is to be DECREASED rather than INCREASED?

And the ratios themselves are decreasing after solutions, how then the seats were increased? could anyone tell me why the ratios decreased instead of increasing?

Dipendra said:   4 years ago
Only increased seats?

How is it possible? Please tell me.

MUKESH said:   4 years ago
7 : 8 = 50 : 70 : 80 then
40% :50% :75% = 70 : 105 : 140.

So, 14 : 21 : 28 = 2 : 3 : 4 is the answer.

Sujith said:   4 years ago
Thanks for the answer @Harjinder.

Afsal said:   5 years ago
If it's decreasing to 40% then what is the answer?

Mahesh said:   5 years ago
Seats for maths, science and arts in a school are in the ratio 5:7:8.there is a proposal to increase these seats by x%, y%, z% respectively. And the ratio of increased seats is 2:3:4. Find x, y, z.

Can anyone solve this?


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