If paint costs $3.10 per quart, and a quart covers 20 square feet, how much will it cost to paint the outside of a cube 10 feet on each edge?  Choose the correct choice from the following answers:
A) $ 1.60  B) $ 16.00  C) $ 93.00  D) $ 108.00  E) $ 196.00

Rationale: "total surface area = 6 a ^ 2 = 6 * 10 * 10 = 600 each quart covers 20 sqr ft thus total number of quarts = 600 / 20 = 30 cost will be 30 * 3.1 = $ 93 ans : c"
Answer: C