Question

A boy runs for 10 min. at a uniform speed of 9 km/hr. At what speed should he run for the next 20 min. so that the average speed is 12 km/hr?

Answer 1

Speed = 9km/h
Time = 10 minutes
Average speed= 12km/h

Total time = 10 + 20
= 30 min

Average speed = Total Distance Travelled / Total Time Taken
Now think and do . Every thi g we should not t

Answer 2

ALOHA...!!ʕ•ٹ•ʔ

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•Distance traveled in 10 mins at speed 9 km/hr = 3/2 km
•Distance traveled in 20 mins at speed x km/hr = x/3 km

•Total dist. = 3/2 + x/3 = (9+2x)/6
•Total time = 30 min ÷ 60 = 1/2 hr

•Average speed = total dist. ÷ total time
12 = (9+2x)/3
36 = 9 + 2x

●x = 27/2 km/hr

✌️__________✌️
―TheShadowHokage―
#FightForTheHallOfFame

I hope this will help u...☺️^-^☺️