Question

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

Answer 1

Hey dear here is your answer!!!

Given:- Average speed = 24km/hr .
Total time = 60 min or 1 hr .
Initial speed = 18
Final speed =?
Let x be the final speed ..
Average speed = Total speed/ Total time
24. =18+x/1
24*1= 18 + x
x=6km/hr .

So he must run at 6km/hr to give out the average of 24km/hr ...

Hope it helps u..