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 3 of 7.
Karthik Pangala said:
7 years ago
@Stark Vin.
We are taking X because ratio means dividing the total quantity into some parts and the number of parts we divide them into is represented in the form of the ratio.
For example, if I have 30 chocolates and if I want to divide them in the ratio 1:2 then first I will see into how many equal parts I need to divide the chocolates into that is 3 in this case why? Because ratio is 1:2 that is to parts I want is 3. That means I need to divide 30 into 3 equal parts and then take 1 part on one side and other part on the other side. This simply means if I divide 30 by 3 I get 10. This means I divided 30 into 3 equal parts where each part contains 10 chocolates. Now I need to divide them in the ratio 1:2 so I take 10 chocolate on one side which is one part of 30 in this example and remaining 2 parts which add up to 20 in other parts. Now 10 by 20 equals 1 by 2 or 1:2 that is what we call as ratio. That is ratio is the representation of total quantity in its simplest form. We could have written it as 10:20 by we need to simplify as much as possible so we take it as 1:2. Now coming to this question we have the boys to girls ratio as 7:8 that simply means the total strength was divide into 7+8 parts but since we do not know what is the total strength we take it as some variable say t now, t by 15 we assume as x. This means now I have divided total strength into 15 equal parts were each part contains x. In that 7x we take as number of boys and 8x as number of girls.
We are taking X because ratio means dividing the total quantity into some parts and the number of parts we divide them into is represented in the form of the ratio.
For example, if I have 30 chocolates and if I want to divide them in the ratio 1:2 then first I will see into how many equal parts I need to divide the chocolates into that is 3 in this case why? Because ratio is 1:2 that is to parts I want is 3. That means I need to divide 30 into 3 equal parts and then take 1 part on one side and other part on the other side. This simply means if I divide 30 by 3 I get 10. This means I divided 30 into 3 equal parts where each part contains 10 chocolates. Now I need to divide them in the ratio 1:2 so I take 10 chocolate on one side which is one part of 30 in this example and remaining 2 parts which add up to 20 in other parts. Now 10 by 20 equals 1 by 2 or 1:2 that is what we call as ratio. That is ratio is the representation of total quantity in its simplest form. We could have written it as 10:20 by we need to simplify as much as possible so we take it as 1:2. Now coming to this question we have the boys to girls ratio as 7:8 that simply means the total strength was divide into 7+8 parts but since we do not know what is the total strength we take it as some variable say t now, t by 15 we assume as x. This means now I have divided total strength into 15 equal parts were each part contains x. In that 7x we take as number of boys and 8x as number of girls.
Naresh said:
8 years ago
7*120/100 = 84/10,
8*110/100 = 88/10,
84/10:88/10 = 84:88.
21:22.
8*110/100 = 88/10,
84/10:88/10 = 84:88.
21:22.
(2)
Charan said:
8 years ago
The total percent of 7x is 100% and they increase 20% so we take it as 120*7x in the same way 110*8x is taken.
Pawan said:
8 years ago
7+8=15.
%= 15+100=150,
7:8 increase by 20% & 10%,
70= 20%=14,
80=10%=8,
Therefore, 70+14=84,
80+8=88,
84:88,
Divide by 4,
Hence new ratio is;
21:22.
%= 15+100=150,
7:8 increase by 20% & 10%,
70= 20%=14,
80=10%=8,
Therefore, 70+14=84,
80+8=88,
84:88,
Divide by 4,
Hence new ratio is;
21:22.
(1)
Abhishek Bansal said:
8 years ago
Given : B : G = 7:8.
This can be written as 7x : 8x ( X being the common multiplier).
Let x = 10 (For simple Calculation)
So Boys = 70 & Girls = 80.
Increased Of Boys by 20% = 70*20/100 = 14.
So After Increase boys would be = 70 + 14 = 84.
Similarly Girls = 80*10/100 = 8 & Girls After Increase would be = 80 + 8 = 88.
New Boys : New Girls = 84:88.
Simply 21:22.
This can be written as 7x : 8x ( X being the common multiplier).
Let x = 10 (For simple Calculation)
So Boys = 70 & Girls = 80.
Increased Of Boys by 20% = 70*20/100 = 14.
So After Increase boys would be = 70 + 14 = 84.
Similarly Girls = 80*10/100 = 8 & Girls After Increase would be = 80 + 8 = 88.
New Boys : New Girls = 84:88.
Simply 21:22.
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.
Muhammad Naeem said:
9 years ago
@Chaitra.
6 * 7 = 42 and 11 * 4 = 44.
6 * 7 = 42 and 11 * 4 = 44.
Chaitra said:
9 years ago
Ramesh sir, how you get 42:44?
Mohanraj said:
9 years ago
The first ratio is 7 increase proposal is 120 (100% + 20%).
The second ratio is 8 increase proposal is 110 (100 + 10%).
The ratio is 7 * 120 = 840 : 8 * 110 = 880.
The answer of the new ratio is 21 : 22.
The second ratio is 8 increase proposal is 110 (100 + 10%).
The ratio is 7 * 120 = 840 : 8 * 110 = 880.
The answer of the new ratio is 21 : 22.
(1)
AJAY said:
9 years ago
7 * 20/100 = 7/5,
7/5 + 7 = 42/5,
8 * 10/100 = 4/5,
4/5 + 8 = 44/5,
42/5 : 44/5 = 21 : 22.
7/5 + 7 = 42/5,
8 * 10/100 = 4/5,
4/5 + 8 = 44/5,
42/5 : 44/5 = 21 : 22.
(1)
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers