Two spherical balls lie on the ground touching. If one of the balls has a radius of 4 cm, and the point of contact is 6 cm above the ground, what is the radius of the other ball?
Choose the correct choice from the following options: A) 10 cm B) 12 cm C) 14 cm D) 16 cm E) 18 cm

Rationale: similar triangle properties . . 2 / r + 4 = 4 / r - 4 giving r = 14 . answer : c
Answer: C