A solid cylinder of radius 3cm has a total surface area of 36(pi)cm2. Find its height

A.
2cm 
B.
3cm 
C.
4cm 
D.
5cm 
E.
6cm
Correct Answer: Option B
Explanation
Area 2(pi)r2 + 2 (pi)r(r + h)
= 2(pi)r(r + h)
36(pi) = 6(pi)(r + h)
36(pi) = 6(pi)(3 + h)
36(pi) = 18(pi) + 6(pi)h
36(pi) – 18(pi) = 6(pi)h
Divide both side by 6(pi)
h = 3cm