PSLE The students of a test are divided equally into two groups. In the first group, there are 52 less girls than boys. In the second group, there are 12 more girls than boys. 40% of all the students are girls. How many students are girls?
|
First group |
Second group |
Total |
Comparison 1 |
50% |
50% |
100% |
Comparison 2 |
Boys (more) |
Girls (less)
|
Boys (less)
|
Girls (more) |
|
|
1 u + 52 |
1 u |
1 u + 20 |
1 u + 20 + 12 |
|
Comparison 3 |
Total girls |
Total boys |
|
|
40% |
60% |
100% |
Number of students in the first group and the second group is equal.
Percentage of students who are boys
= 100% - 40%
= 60%
Percentage of more boys than girls
= 60% - 40%
= 20%
Total number of boys
= 1 u + 52 + 1 u + 20
= 2 u + 72
Total number of girls
= 1 u + 1 u + 20 + 12
= 2 u + 32
Number of boys more than girls
= 72 - 32
= 40
20% of the students = 40
1% of the students = 40 ÷ 20 = 2
40% of the students
= 40 x 2
= 80
Number of students that are girls = 80
Answer(s): 80