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:
88 comments Page 2 of 9.
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)
Mahesh said:
7 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?
Can anyone solve this?
Saif said:
9 years ago
@Aparna it is correct and the right way to solve this problem.
After this, you compare the ratio.
7/20 : 21/40 : 7/10.
Now bring the denominator to 40.
14/40 : 21/40 : 28/40.
14 : 21 : 28.
Simplify by 7.
2 : 3 : 4.
After this, you compare the ratio.
7/20 : 21/40 : 7/10.
Now bring the denominator to 40.
14/40 : 21/40 : 28/40.
14 : 21 : 28.
Simplify by 7.
2 : 3 : 4.
Himanshu said:
6 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?
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?
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.
RAHUL SINGH said:
1 decade ago
Let their Ratio be 5X,7X,8X. INCRISED %=140%,150%,175%
ATQ , 5X OF 140=7X,150%OF 7X=21/2X,175%OF 8X=12.
Their Ratio = 7X:21/2X:14X.
Taking LCM of Denominator, we get = 14:21:28=2:3:4
ATQ , 5X OF 140=7X,150%OF 7X=21/2X,175%OF 8X=12.
Their Ratio = 7X:21/2X:14X.
Taking LCM of Denominator, we get = 14:21:28=2:3:4
Richa said:
1 decade ago
@ shwetha
when it is said that there is x% or y% increase in any value then to find out that increased value we have do
100+x
as in this example a value increased 40% means 100+40=140
when it is said that there is x% or y% increase in any value then to find out that increased value we have do
100+x
as in this example a value increased 40% means 100+40=140
Aparna said:
1 decade ago
5x/20+5/20*40/100 = 7x/20.
7x/20+7x/20*50/100 = 21x/40.
8x/20+8x/20+75/100 = 7x/10.
Can any one help me is it correct if yes what are the next steps please help me to understand.
7x/20+7x/20*50/100 = 21x/40.
8x/20+8x/20+75/100 = 7x/10.
Can any one help me is it correct if yes what are the next steps please help me to understand.
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.
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.
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