In a school, 0.75 of the boys and 0.1 of the girls take part in sports. There is an equal number of girls and boys who do not take part in sports. If 306 children do not take part in sports, how many more children 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
3x9	1x9	1	9
	1x9		1x9
27 u	9 u	1 u	9 u

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

0.1 = ¹₁₀
Girls that take part : Girls that do not take part = 1 : 9

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 9 is 9.

Number of children who do not take part in sports
= 9 u + 9 u
= 18 u

18 u = 306

1 u = 306 ÷ 18 = 17

Number of children who take part in sports
= 27 u + 1 u
= 28 u

Number of more children who take part in sports than those who do not take part in sports
= 28 u - 18 u
= 10 u
= 10 x 17
= 170

Answer(s): 170