Question

A boy runs from 10 min at a uniform speed 9lm/h. At what speed should he run for the next 20
min so that the average speed comes to 12 km/h?​

Answer 1

Explanation:

t1=10*60

s1=9

d1=9*10*60

t2=20*60

s2=12

d2=12*20*60