Question 89939
let b equal number of boys, so number of girls is 500-b


1/3 of the boys play soccer and twice as many girls as boys play soccer ... 100 of the girls do not play soccer


so 500-b-100 girls play soccer and this number is twice a large as the 1/3 of the boys that play


500-b-100=2(b/3) ... 400=5b/3 ... 1200=5b ... 240=b