Question

Water is being poured into a conical cup that is 12cm tall.
a) When the water in the cup is 9cm deep, what percentage of the cup is filled?
b) When the cup is 75 percent filled, how deep is the water?

Answer 1

9/12 = 0.75 = 75%

Answer 2

The cup is a cone, not a cylinder.

9/12 = 3/4, so the volume is (3/4)^2 = 9/16 = 56.25%

When 75% is full, the depth is √.75 = 0.866, or 10.39 inches

Answer 3

But what about the radius