11. A traincovers four successive 7 kmdistances at speeds of 10 km/hou

1.	11. A traincovers four successive 7 kmdistances at speeds of 10 km/hour, 20km/hour, 30 km/hour and 60 km/hourrespectively. Its average speed over thisdistance isčł?
Answer» Total distance covered = 74 = 28 km Total time taken = (7/10 + 7/20 + 7/30 + 7/60) = 42+21+14+7/60 = 84/60 = 7/5 hours average speed = Total distance/total time = 28/(7/5) = 45 = 20 kmph Like my answer if you find it useful!

11. A traincovers four successive 7 kmdistances at speeds of 10 km/hour, 20km/hour, 30 km/hour and 60 km/hourrespectively. Its average speed over thisdistance isčł?

Answer»

Total distance covered = 7*4 = 28 km

Total time taken = (7/10 + 7/20 + 7/30 + 7/60)

= 42+21+14+7/60

= 84/60

= 7/5 hours

average speed = Total distance/total time

= 28/(7/5)

= 4*5

= 20 kmph

Like my answer if you find it useful!