Question

speed for the entire journey is 60km/h? (ans. 90km/hr)
(e) A boy runs for 10 min. at a uniform speed of 9km/h. At what speed should he run for the next 20 min. so that
the average speed comes 12km/hr? (ans. 13.5km/h)
Give reasons for the following:​

Answer 1

Explanation:

A boy runs for 10 min at a uniform speed of 9 km/h. At what speed should be run for the next 20 min so that the average ...