PSLE The students of a test are divided equally into two groups. In the first group, there are 47 less girls than boys. In the second group, there are 13 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 + 47 |
1 u |
1 u + 17 |
1 u + 17 + 13 |
|
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 + 47 + 1 u + 17
= 2 u + 64
Total number of girls
= 1 u + 1 u + 17 + 13
= 2 u + 30
Number of boys more than girls
= 64 - 30
= 34
20% of the students = 34
1% of the students = 34 ÷ 20 = 1.7
40% of the students
= 40 x 1.7
= 68
Number of students that are girls = 68
Answer(s): 68