The volume of a cone is given by the formula:

Given,
D = 6 and H = 10 [D is Diameter and H is Height]
(note: radius is half of diameter. Diameter given is 6, so radius is 3)
Plugging r = 3 & h = 10 into the formula above, we get:

In decimal, it is,

ANSWER: 30
cubic units OR 94.2 cubic units