Answer:
64
Explanation:
Distance traveled in 2 hours = 2 * 40 = 80 m
Distance traveled in 3 hours = 3 * 80 = 240m
Total distance covered = 240 + 80 = 320m
Total time = 2 + 3 =5 h
Hence avg speed = total distance covered / total time taken
= 320/5 = 64mph
