How many paying stones, each measuring 2 m * 2 m are required to pave a rectangular court yard 30 m long and 18 m board?  Pick:
A) 99 B) 18 C) 135 D) 17 E) 12

Rationale: "30 * 18 = 2 * 2 * x = > x = 135 answer : c"
Answer: C