Sean has 12 cylindrical containers filled with sand, each of which has a radius of 4 centimeters. He wants to transfer his sand into some new cylindrical containers, which are the same height but have a radius of 6 centimeters. How many new containers will Sean need?
Cylinder volume pi r^2 h
12 * pi r12 h / (pi r22 h) = # of larger needed
12 (4)^2 / ( (6^2) = 5 1/3 =~ 6 cylinders of 6 cm