PSLE The students of a test are divided equally into two groups. In the first group, there are 47 less boys than girls. In the second group, there are 21 less girls than boys. 40% of all the students are boys. How many students are there altogether?
|
First group |
Second group |
Total |
Comparison 1 |
50% |
50% |
100% |
Comparison 2 |
Girls (more) |
Boys (less) |
Girls (less)
|
Boys (more) |
|
|
1 u + 47 |
1 u |
1 u + 13 |
1 u + 13 + 21 |
|
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 + 47 + 1 u + 13
= 2 u + 60
Total number of boys
= 1 u + 1 u + 13 + 21
= 2 u + 34
Number of girls more than boys
= 60 - 34
= 26
20% of the students = 26
1% of the students = 26 ÷ 20 = 1.3
100% of the students
= 100 x 1.3
= 130
Number of students = 130
Answer(s): 130