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:
64 comments Page 7 of 7.
SRIPAL S said:
1 decade ago
@Kiran Kumar
note that something we included to get 20%
For example the ratio of the ratio of to boys ages was 5:2
we can write it as 5x : 2x we get exact ratio we will not consider it alone
For that way 7x 8x will appear
then
to covert 20% into no. it will be 20/100
note that the unknown was x
then 20/100x*x
so we take common one x(20/100+1)
so x(20/100+100)
x(120/100)
that was we get 120/100
forget x because that x which is in 7x both are same so we get 120/100*7x
note that something we included to get 20%
For example the ratio of the ratio of to boys ages was 5:2
we can write it as 5x : 2x we get exact ratio we will not consider it alone
For that way 7x 8x will appear
then
to covert 20% into no. it will be 20/100
note that the unknown was x
then 20/100x*x
so we take common one x(20/100+1)
so x(20/100+100)
x(120/100)
that was we get 120/100
forget x because that x which is in 7x both are same so we get 120/100*7x
ABHINESH said:
2 decades ago
(7x+0.2*7x)/(8x+0.1*8x)=21:22
Ramesh said:
2 decades ago
7:8 can also be written as 70:80
120/100*70 = 84
110/100*80 = 88
so,new ratio= 84 : 88
or 42 : 44
or 21 : 22
120/100*70 = 84
110/100*80 = 88
so,new ratio= 84 : 88
or 42 : 44
or 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.
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