In a school, 0.9 of the girls and 0.1 of the boys take part in sports. There is an equal number of boys and girls who do not take part in sports. If 198 children do not take part in sports, how many more children take part in sports than those who do not take part in sports?

Girls		Boys
Take part	Do not take part	Take part	Do not take part
9x9	1x9	1	9
	1x9		1x9
81 u	9 u	1 u	9 u

0.9 = ⁹₁₀
Girls that take part : Girls that do not take part = 9 : 1

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

The number of boys who do not take part is repeated.  Make the number of boys 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 = 198

1 u = 198 ÷ 18 = 11

Number of children who take part in sports
= 81 u + 1 u
= 82 u

Number of more children who take part in sports than those who do not take part in sports
= 82 u - 18 u
= 64 u
= 64 x 11
= 704

Answer(s): 704