Two pedestrians left the same point and walked in the same direction. 10 minutes later, one pedestrian was ahead

Two pedestrians left the same point and walked in the same direction. 10 minutes later, one pedestrian was ahead of the other by 100 meters. What was the speed of the second pedestrian if 1 was 60 m / min?

1) 100/10 = 10 (m) – equals lead per minute.
2) 60 + 10 = 70 (m) per minute the second pedestrian was moving.
3) 70 * 60 = 4200 m
4) 4200 = 4.2 km per hour
Answer: 4.2 km per hour speed of the second pedestrian.