Question

The height of a right cylinder is 3 times the radius of the base. The volume of the cylinder is 242

What is the height of the cylinder?
2 units
4 units
6 units
8 units

Answer 1

D

Explanation:

Formula

Volume = pi*r^2*h

Givens

r = x

h = 3x

Volume= 242

Solution

242 = pi * x^2 * 3x

242 = 3.14 * 3x^3 Divide by pi

242/3.14 = 3.14 * 3x^3 / 3.14 Do the division

77 = 3x^3 Divide by 3

77/3 = 3x^3 /3

25.69 = x^3 Take the cube root of both sides.

2.95 = x

The height of the cylinder is 3 times that of the radius of the circle (x)

The answer is 8.85. I suppose the closest answer is 8.