there are 3 boys for every 4 girls.how many are boys in a class of 42?

2 answers

3 + 4 = 7

42 / 7 = 6

Boys : 6 * 3 = 18

Girls : 4 * 6 = 24
let the number of boys be 3x and the number of girls be 4x
2x+4x = 42
7x=42
x=6
so we have 3x or 18 boys and 4x or 24 girls.