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?
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:
89 comments Page 3 of 9.
Bharadwaj said:
1 decade ago
Ramesh and Harjinder was explained well :).
Nikhil said:
1 decade ago
@Harjinder can you please tell me how do we find out?
1. 40% of 5 = 2, total seats 5+2 = 7.
2. 50% of 7 = 7/2 total seats 7+7/2 = 21/2.
3. 75% of 8 = 6 total seats 8+6 = 14.
1. 40% of 5 = 2, total seats 5+2 = 7.
2. 50% of 7 = 7/2 total seats 7+7/2 = 21/2.
3. 75% of 8 = 6 total seats 8+6 = 14.
Bala said:
1 decade ago
Why we should add 100+x?
Mk.raj said:
1 decade ago
Because% mean 100, than 40% increase means 140.
Sarika said:
1 decade ago
Ratio is 5:7:8.
Increase in % i.e 140, 150 and 175.
Then, 5*140 = 700.
7*150 = 1050.
8*175 = 1400.
Ratio = 700:1050:1400.
70:105:140.
Answer = 2:3:4.
Increase in % i.e 140, 150 and 175.
Then, 5*140 = 700.
7*150 = 1050.
8*175 = 1400.
Ratio = 700:1050:1400.
70:105:140.
Answer = 2:3:4.
Faizan said:
1 decade ago
Previous ratio is 5:7:8, now by adding increase.
we get,
5+0.4*5 : 7+0.5*7 : 8+0.75*8 , which is 7:10.5:14.
Now it is simplified as 70:105:140 (by multiplying 10 with all).
And on simplifying by 7, we get new ratio as 2:3:4 .
we get,
5+0.4*5 : 7+0.5*7 : 8+0.75*8 , which is 7:10.5:14.
Now it is simplified as 70:105:140 (by multiplying 10 with all).
And on simplifying by 7, we get new ratio as 2:3:4 .
(1)
Aaanikt said:
1 decade ago
5/2 = 2.5(approx 2).
7/2 = 3.5(approx 3).
8/2 = 4.
Than ratio is 2:3:4.
7/2 = 3.5(approx 3).
8/2 = 4.
Than ratio is 2:3:4.
Ramesh said:
1 decade ago
Say the ratio is 5:7:8. What is their denominator and how it has come. And if it is 20 then wouldn't it be like this 15x/20x = 140/100 and 7x/20x= 150/100. Does 15/20 indicates 100 percent here.
Barun nag said:
1 decade ago
How 14x:21x:28x becomes 2:3:4?
Ganesh said:
1 decade ago
Hey @Barun.
14/7, 21/7, 28/7.
14/7, 21/7, 28/7.
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