Math
posted by Losa .
I don't get the first problem of my homework. We learned three lessons today, the increase, decrease, and finding the base number. But i don't know which one I should use. Please help with this problem: There are 12 girls in Mr. Cooper's class. The girls make up 40% of the class. How many students are in the class?

girls = 0.4 * total
so
12 = 0.4 * total
so
total = 12 / 0.4
total = 30
check:
0.4 * 30 = 12 yes