Question

Andy wants to build a circular concrete patio in his backyard and install a jungle gym on top of it. One 80-lb bag of concrete will be enough for 2 square feet. If he wants the diameter of the patio to be 10 ft, how many bags of concrete will he need to purchase?

Answer 1

A. 20
B. 40
C. 80
D. 158

Answer 2

Try doing the cross method:

Answer 3

So your answer is 40 which id B