Question

The cone shown has a height of 5 inches and a radius of 1.5 inches. What is the approximate volume of the cone?

A. Between 11 and 12 cubic inches
B. Between 15 and 16 cubic inches
C. Between 35 and 36 cubic inches
D. Between 39 and 40 cubic inches

From what I've seen the answer is A, but with what I did from the cone volume formula I know (pi x r^2 x h) it's around 35, so I'm a bit confused

Answer 1

You have the wrong formula for volume

the volume of a cone = (1/3)π r^2 h
since you want an approximation, I would guess at (1/3)(3)(9/4)(5)
= 45/4 = 11.25

(actual answer = (1/3)(π)(9/4)(5) = (15/4)π = 11.781 correct to 3 decimals )

Answer 2

I got it now, thank you