Question

An 8 unit x 8 unit x 8 unit cube is composed of smaller 1 unit cubes and is painted blue. How many of the 1 unit cubes have exactly 1 face painted blue?

A. 72
B. 296
C. 216
D. 512

Answer 1

The correct answer is C. 216. There are eight 1-unit cubes on each side of the larger 8-unit cube, and six faces in total for each smaller cube. Therefore, 6 x 8 = 48 smaller cubes have at least 1 face painted blue. Then, 48 divided by 2 = 24, which is the number of cubes with exactly 1 face painted blue.