If there are 65% girls in a class and there are 12 more girls than boys then how many boys are there in the class?
g = b + 12
b+12 = .65 (b+12+b)
b + 12 = .65 (2 b) + 7.8
4.2 = .3 b
b = 14
b+12 = .65 (b+12+b)
b + 12 = .65 (2 b) + 7.8
4.2 = .3 b
b = 14