Question

a runner runs 100m in 10s, then turns around and jogs 50m back toward the starting point in 30s. then avg speed.

Answer 1

average speed=total distance covered/total time taken
so avg speed =100+50/10+30
=150/40
=15/4

Answer 2

Vav= total distance/ total time
=100+50/10+30
=150/40
=3.75m/s