Question

A water cup in the shape of a cone has a height of 4 inches and a maximum diameter of 3 inches. What is the volume of the water in the cup, to the nearest tenth of a cubic inch, when the cup is filled to half its height?

Answer 1

The diameter of half the cone is equal to half of the given diameter and its height is also half the given height. 
                                   V = 1/3(πr²)(h)
d = 1.5 inches, r = 0.75 inches
h = 2 inches

Substituting,
                                   V = 1/3(π)(0.75 in)²(2 in)
                                          V = 1.178 in³