CAYLEY 2017 Problem 3

A snowman is built by stacking three spheres with their centers aligned vertically. The spheres have radii of 10\:cm,20\:cm and 30\:cm.

Image
How tall is the snowman?

Answer Choices
A. 90\:cm
B. 100\:cm
C. 110\:cm
D. 120\:cm
E. 130\:cm