Question

A train travels 200 Km at a speed of 80 Km/hr. How fast should it travel on its return so that the avg speed is 100 Km/hr??

Answer 1

Answer:

133 km ph approximately

Explanation:

As we know that

=> total distance / total time taken = average speed

now given

distance = 400 km (200+200 for return)

average speed = 100 kmph

now let us consider that total time taken is X hours so

400/X= 100

it gives 4 hours it means 4 hours taken to cover 400 km but 200 km we had already covered with a speed of 80 kmph

i.e 200/80= 2.5

it means out of 4 hours 2.5 hours spent

now remaining time is for remaining trip

=> = 200/4-2.5

=> 200/1.5 = 133 kmph aprox