# CAT Practice : Percents, Profits

50% more than x is 1.5x. Simple, very useful idea.

## Percentages - Classroom

Q.9: Class B has 50% more students than class A. Number of girls in class A is equal to number of boys in class B. The percentage of girls is the same in both classes. What percentage of the student group are boys?
1. 33.33%
2. 40%
3. 25%
4. 60%

Choice B. 40%

## Detailed Solution

Let number of girls in class A = x
Let number of boys in class A = y
Total number of students = x + y
Proportion of girls = ${x \over x + y}$

Number of boys in class B = x
Total number of students in class B = 1.5( x + y)
Proportion of girls = ${1} {-} {x \over 1.5 (x + y)}$

Percentage of boys in the overall student community = ${x + y \over 2.5}$ * (x + y) * 100 = 40%. Choice (B)

## Our Online Course, Now on Google Playstore!

### Fully Functional Course on Mobile

All features of the online course, including the classes, discussion board, quizes and more, on a mobile platform.

### Cache Content for Offline Viewing

Download videos onto your mobile so you can learn on the fly, even when the network gets choppy!

## More questions from Averages, Ratios, Mixtures

A number of beautiful questions from three allied topics. Most sportsmen will tell you - If you know the percentage play, you can profit well from it,