Question

The formula for finding the volume of a cone is V = 1 3 πr2h. The volume of a cone is 300 cm3 and the height of the cone is 10 cm. What is the approximate radius of the cone? A) 3 cm B) 5 cm C) 9 cm D) 28 cm

Answer 1

You could plug each answer choice into the formula along with the given information and see which answer works.
***It helps to have a calculator do the quick calculations

A) r = 3 cm → 300 =
`(1)/(3) \pi * 3^(2) *10` ≈ 94.2 NOT IT

B) r = 5 cm → 300 =
`(1)/(3) \pi* 5^(2) *10` ≈ 261.7 THE CLOSEST

C) r = 9 cm → 300 =
`(1)/(3) \pi* 9^(2) *10` ≈ 848.2 NOT IT

D) r = 28 cm → 300 =
`(1)/(3) \pi* 28^(2) *10` ≈ 8210.02 NOT IT