Question

A boy runs for 20 min at a uniform speed of 18km/h at what speed should he run for the next 40 min so that the average speed comes 24km/hr

Answer 1

Average speed= 12 km/hr
total distance/ total time
D1+D2/T1+T2
Total time= 20+40min=60 min
=1hour
D1= Speed *time = 9*1/3(20min

=1/3hr)
=3km
D2=?
24= 3+ D2/1
24-3=D2
D2=21km
Speed= Distance/time
=21/40/60
= 21/2/3
=31.5km/hr

Answer 2

Answer:

Your answer is on the above attachment

Hope this helps you.