In a school, 0.75 of the boys and 0.7 of the girls take part in charity work. There is an equal number of girls and boys who do not take part in charity work. If 84 students do not take part in charity work, how many more students take part in charity work than those who do not take part in charity work?
Boys |
Girls |
Take part |
Do not take part |
Take part |
Do not take part |
3x3 |
1x3 |
7 |
3 |
|
1x3 |
|
1x3 |
9 u |
3 u |
7 u |
3 u |
0.75 =
34 Boys that take part : Boys that do not take part = 3 : 1
0.7 =
710 Girls that take part : Girls that do not take part = 7 : 3
The number of girls who do not take part is repeated. Make the number of girls who do not take part the same. LCM of 1 and 3 is 3.
Number of students who do not take part in charity work
= 3 u + 3 u
= 6 u
6 u = 84
1 u = 84 ÷ 6 = 14
Number of students who take part in charity work
= 9 u + 7 u
= 16 u
Number of more students who take part in charity work than those who do not take part in charity work
= 16 u - 6 u
= 10 u
= 10 x 14
= 140
Answer(s): 140