Question

A cylinder has a surface area of 156π square inches and a diameter of 12 in. What is the height of the cylinder?

Answer 1

In this question , the surface area is given which is 156 pi and a diameter of 12 in .

Radius is half of diameter, so radius is 6 in .

Now we use the formula of surface area of cylinder which is

$Area = 2 \pi r^2 + 2 \pi r h$

$156 \pi = 2 \pi (6)^2 + 2 \pi *6*h$

Dividing both sides by 2 pi

$78 = 36 + 6h$

Subtracting both sides by 36,

$42 = 6h \\ h = 7 in$

Correct option is B

Answer 2

B is correct answer. There are 7 inches of the height of the cylinder. Hope this helps. Thank you!