Aptitude - Ratio and Proportion - Discussion
Discussion Forum : Ratio and Proportion - General Questions (Q.No. 6)
6.
The ratio of the number of boys and girls in a college is 7 : 8. If the percentage increase in the number of boys and girls be 20% and 10% respectively, what will be the new ratio?
Answer: Option
Explanation:
Originally, let the number of boys and girls in the college be 7x and 8x respectively.
Their increased number is (120% of 7x) and (110% of 8x).
![]() |
![]() |
120 | x 7x | ![]() |
and | ![]() |
110 | x 8x | ![]() |
100 | 100 |
![]() |
42x | and | 44x |
5 | 5 |
![]() |
![]() |
42x | : | 44x | ![]() |
= 21 : 22. |
5 | 5 |
Discussion:
61 comments Page 5 of 7.
Narayana Rao Gartam said:
1 decade ago
20% of 70 is 14 (20/100*70) So, Total increase is 84.
10% of 80 is 8 So, total increase is 88.
Ratio of 84/88 = 21/22,
i.e 21:22.
10% of 80 is 8 So, total increase is 88.
Ratio of 84/88 = 21/22,
i.e 21:22.
Md shahrukh said:
1 decade ago
Let the no of boys 7 and girls 8.
7x120/100: 8x110/100.
840:880.
So answer is 21:22.
7x120/100: 8x110/100.
840:880.
So answer is 21:22.
Atul1487 said:
1 decade ago
Boys: Girls.
7:8.
20% increase in boys no. so,
7*20% = 1.4 so total boys = 7+1.4 = 8.4.
10% increase in girls.
8*10% = 0.8 So total Girls = 8+0.8 = 8.8.
So Ratio of Boys & Girls.
8.4 : 8.8.
21:22 Answer.
7:8.
20% increase in boys no. so,
7*20% = 1.4 so total boys = 7+1.4 = 8.4.
10% increase in girls.
8*10% = 0.8 So total Girls = 8+0.8 = 8.8.
So Ratio of Boys & Girls.
8.4 : 8.8.
21:22 Answer.
Stark Vin said:
1 decade ago
Hi all,
One minor doubt, why we are using for every question for ratio, what x mean? is a assumed value or what ? for this question if we didn't use x also we are getting the answer, but in other cases, we need to use X, please suggest me a good method.
Thanks.
One minor doubt, why we are using for every question for ratio, what x mean? is a assumed value or what ? for this question if we didn't use x also we are getting the answer, but in other cases, we need to use X, please suggest me a good method.
Thanks.
Gowtham said:
1 decade ago
Simply find 20% of 7 and 10% of 8.
It will be 1.4 and 0.8 respectively.
Till this ok then,how 8.4:8.8.
And how to convert it into fraction.
So the ratio is 8.4:8.8.
Then convert the fraction into whole numbers.
If I multiply by 10 I will get 84:88 now we can easily simplify it.
So we get 21:22.
It will be 1.4 and 0.8 respectively.
Till this ok then,how 8.4:8.8.
And how to convert it into fraction.
So the ratio is 8.4:8.8.
Then convert the fraction into whole numbers.
If I multiply by 10 I will get 84:88 now we can easily simplify it.
So we get 21:22.
Nive said:
1 decade ago
Simply find 20% of 7 and 10% of 8.
It will be 1.4 and 0.8 respectively.
So the ratio is 8.4:8.8.
Then convert the fraction into whole numbers.
If I multiply by 10 I will get 84:88 now we can easily simplify it.
So we get 21:22.
It will be 1.4 and 0.8 respectively.
So the ratio is 8.4:8.8.
Then convert the fraction into whole numbers.
If I multiply by 10 I will get 84:88 now we can easily simplify it.
So we get 21:22.
Zahir said:
1 decade ago
20%of7 = 7/5 that means boys total = 7+7/5.
=42/5.
10%of8 = 4/5 that means girls total = 8+4/5 = 44/5.
Boys : Girls = 42/5:44/5.
=42:44.
=21:22.
=42/5.
10%of8 = 4/5 that means girls total = 8+4/5 = 44/5.
Boys : Girls = 42/5:44/5.
=42:44.
=21:22.
Pankaj said:
1 decade ago
There is some problem to understand the problem ie question is asked 20% and 10% but here get 120% and 110% why ?
Sunali said:
1 decade ago
Thanks priyabhrt.
Prasanna said:
1 decade ago
@rajeev.
Yes you get the same answers.
Yes you get the same answers.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers