posted by lovecaandy .
If a 4th grade with 140 students has 3 boys for every 4 girls how many are girls? how many are boys?
Set up a proportion and cross multiply. Let x = the number of boys
3/7 = x/140
7x = 420
x = 60
there are 80 fourth graders in school of these, 35 were boys. what fractional part of the fourth graders were girls