Here is the question:
Patty has a bag of 72 marbles. The ratio of green marbles to yellow marbles is 2 to 7. How many green marbles does patty have?
I don't know how to answer it. Please help!
Yellow : green = 7 : 2
2 in 9 marbles are green,
x in 72 are green,
so cross-multiply to get
x=2*72/9=16 green marbles out of 72.