In a school, 0.75 of the boys and 0.3 of the girls take part in sports. There is an equal number of girls and boys who do not take part in sports. If 84 students do not take part in sports, how many more students take part in sports than those who do not take part in sports?

Boys		Girls
Take part	Do not take part	Take part	Do not take part
3x7	1x7	3	7
	1x7		1x7
21 u	7 u	3 u	7 u

0.75 = ³₄
Boys that take part : Boys that do not take part = 3 : 1

0.3 = ³₁₀
Girls that take part : Girls that do not take part = 3 : 7

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 7 is 7.

Number of students who do not take part in sports
= 7 u + 7 u
= 14 u

14 u = 84

1 u = 84 ÷ 14 = 6

Number of students who take part in sports
= 21 u + 3 u
= 24 u

Number of more students who take part in sports than those who do not take part in sports
= 24 u - 14 u
= 10 u
= 10 x 6
= 60

Answer(s): 60