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 |
 The required ratio = |
|
42x | : | 44x | |
= 21 : 22. |
| 5 | 5 |
Discussion:
63 comments Page 5 of 7.
Priyabrata said:
1 decade ago
20% of 7=14/10,total increase 7+14/10=84/10
10% of 8=8/10,total increase 8+8/10=88/10
now compare ratio of Boys and Girls
84/10:88/10
or 84:88
or 42:44
or 21:22
10% of 8=8/10,total increase 8+8/10=88/10
now compare ratio of Boys and Girls
84/10:88/10
or 84:88
or 42:44
or 21:22
Kavya said:
1 decade ago
I am getting 7:4 by whichever method I do. I am not satisfied with any explanations given. Help me.
Rajeev said:
1 decade ago
@ ramesh
Can you tell you multiply 70 & 80 instead of 7 & 8, as we get same answer in both the cases?
Can you tell you multiply 70 & 80 instead of 7 & 8, as we get same answer in both the cases?
Prasanna said:
1 decade ago
@rajeev.
Yes you get the same answers.
Yes you get the same answers.
Sunali said:
1 decade ago
Thanks priyabhrt.
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 ?
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.
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.
K.kiran kumar said:
2 decades ago
I can not get that how 120% of 7x and 110% of 8x.
Please someone explain it.
Please someone explain it.
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.
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