PSLE
The students of a test are divided equally into two groups. In the first group, there are 42 more girls than boys. In the second group, there are 2 more boys than girls. 40% of all the students are boys. How many students are girls?

	First group		Second group		Total
Comparison 1	50%		50%		100%
Comparison 2	Girls (more)	Boys (less)	Girls (less)	Boys (more)
	1 u + 42	1 u	1 u + 20	1 u + 20 + 2
Comparison 3	Total boys		Total girls
	40%		60%		100%

Number of students in the first group and the second group is equal.

Percentage of students who are girls
= 100% - 40%
= 60%

Percentage of more girls than boys
= 60% - 40%
= 20%

Total number of girls 
= 1 u + 42 + 1 u + 20
= 2 u + 62

Total number of boys
= 1 u + 1 u + 20 + 2
= 2 u + 22

Number of girls more than boys
= 62 - 22
= 40

20% of the students = 40

1% of the students = 40 ÷ 20 = 2

60% of the students
= 60 x 2
= 120

Number of students that are girls = 120

Answer(s): 120