Richard walks along Sunrise Boulevard daily. He starts walking at 07:00 from block 10 and walks to block 90 where he turns around and walks back to block 70, where he stops at 07:30. The blocks along the boulevard are numbered sequentially (1,2,3), and each block measures 40 meters. What is Richard's speed in meters per minute? Choose the most appropriate option
A) 75 B) 180 C) 198 D) 216 E) 252

Rationale: total distance from 10 to 90 = 80 + from 90 to 70 = 20 so the dist is 100 × 30 ( per block dist ) speed = 3000 mts / 40 min = 75 m / min a is the answer
Answer: A