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:
61 comments Page 3 of 7.
Ankita said:
1 decade ago
Why we use decimal values instead of fraction value?
20% of 7 = 7/5.
10% of 8 = 4/5.
7/5:4/5 = 7:4.
So answer should be 7+7:4+8 = 14:12.
20% of 7 = 7/5.
10% of 8 = 4/5.
7/5:4/5 = 7:4.
So answer should be 7+7:4+8 = 14:12.
Anjan said:
2 years ago
The ratio of B:G = 7:8,
7 increased 20% = 7 * 20/100 = 7/5.
8 increased 10% = 8 * 10/100 = 4/5.
7 + 7/5 = 8+4/5,
= 42/5 = 44/5,
= 21:22.
7 increased 20% = 7 * 20/100 = 7/5.
8 increased 10% = 8 * 10/100 = 4/5.
7 + 7/5 = 8+4/5,
= 42/5 = 44/5,
= 21:22.
(42)
Ravi said:
6 years ago
For boys :- 7+20/100. that is 36/5.
And for girls:- 8+10/100.that is 81/10.
Then ATQ. 36/5*10/81.
And answer will become 8:9.
And for girls:- 8+10/100.that is 81/10.
Then ATQ. 36/5*10/81.
And answer will become 8:9.
(2)
RAJ said:
1 decade ago
RAMESH very well said. ! keep posting your SHORTCUT method. Its very useful for us. !i search at every discussion. Because of you. !
Yamini saraswathi said:
8 years ago
Actually, I am getting answer as a
(120/100)*7=8.4 so approximately = 8.
(110/100)*8=8.8 so approximately = 9.
The answer is 8:9.
(120/100)*7=8.4 so approximately = 8.
(110/100)*8=8.8 so approximately = 9.
The answer is 8:9.
Aditya said:
1 decade ago
We also 7:8 is 70:80.
So 20% and 10% =120 and 110.
Then 70*120 = 840, 110*8 = 880.
Simply divide them, 840/880 = 21/22 (Answer).
So 20% and 10% =120 and 110.
Then 70*120 = 840, 110*8 = 880.
Simply divide them, 840/880 = 21/22 (Answer).
Ramesh said:
1 decade 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
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.
Prakash said:
1 decade ago
Please tell me easy steps or tricks to find ratios in complex cases without working a lot of steps!
I m waiting! for your reply.
I m waiting! for your reply.
Khushboo said:
1 decade ago
Why do we multiply 120% by 7x and 100% by 8x
Why not we simply multiply 20% by 7x and 10% by 8x ?
Please someone explain me.
Why not we simply multiply 20% by 7x and 10% by 8x ?
Please someone explain me.
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