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 2 of 7.
Akash said:
3 years ago
Herre the ration is; 7:8.
We take it as 7x : 8x.
Assume x = 10.
Then 7*10 : 8 * 10.
70 : 80.
Increment boys = 20%
The 70s 20% is 14.
So we add 70+14 = 84.
Similarly, we calculate girl's increment for 10%.
80s 10% is 8.
So we add 80 + 8 = 88
Finally 84 : 88
Divide it by 4.
And We get 21 : 22.
We take it as 7x : 8x.
Assume x = 10.
Then 7*10 : 8 * 10.
70 : 80.
Increment boys = 20%
The 70s 20% is 14.
So we add 70+14 = 84.
Similarly, we calculate girl's increment for 10%.
80s 10% is 8.
So we add 80 + 8 = 88
Finally 84 : 88
Divide it by 4.
And We get 21 : 22.
(29)
Waquar said:
6 years ago
Thanks @Priyabrata.
(3)
Sam said:
6 years ago
Given 7:8.
They said there is 20% and 10% increase in this ratio
Which means with this 7 , there is 20% increase of 7 .similarly for 8
That is;
7 + 7 * 20/100 : 8+8*10/100.
7+ 7/5 : 8+4/5,
21:22.
They said there is 20% and 10% increase in this ratio
Which means with this 7 , there is 20% increase of 7 .similarly for 8
That is;
7 + 7 * 20/100 : 8+8*10/100.
7+ 7/5 : 8+4/5,
21:22.
(10)
Raghual R said:
6 years ago
We can write 7:8 as 7x and 8x . If x = 1000.
Then 7000 : 8000.
20% of 7000 = 1400 then total boys = 7000+1400 = 8400;
10% of 8000 = 800 then total girls = 8800.
So the new ratio is 8400:8800 which is 21:22.
Then 7000 : 8000.
20% of 7000 = 1400 then total boys = 7000+1400 = 8400;
10% of 8000 = 800 then total girls = 8800.
So the new ratio is 8400:8800 which is 21:22.
(5)
Yudhisthira sarapuria said:
6 years ago
20% increase mean 120/100 = 6/5.
(4)
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)
GANESH DEY said:
6 years ago
Please tell me, why denominator 5 is removed?
(4)
Abhishek chaturvedi said:
6 years ago
Let the boys be 7x and girls be 8x.
Boys 20 percent = 7x * 20/100 = 7X/5.
Girls 10 percent = 8x * 10/100 = 4x/5.
Total boys = 7X + 7x/5 = 42x/5.
Total girls = 8x+ 4x/5 = 44x/5.
So, ratio;
Total boys : total girls = 42x/5 /44x/5 = 22/22 = 21:22.
Boys 20 percent = 7x * 20/100 = 7X/5.
Girls 10 percent = 8x * 10/100 = 4x/5.
Total boys = 7X + 7x/5 = 42x/5.
Total girls = 8x+ 4x/5 = 44x/5.
So, ratio;
Total boys : total girls = 42x/5 /44x/5 = 22/22 = 21:22.
(1)
Siva said:
7 years ago
Can you say, how 42/5 : 44/5 = 21:22? Please explain clearly.
(4)
Aman said:
7 years ago
7 : 8 = 70 : 80.
70 * 120/100 = 84,
80 * 110/100 = 88,
So, 84:88 = 21:22.
70 * 120/100 = 84,
80 * 110/100 = 88,
So, 84:88 = 21:22.
(4)
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