Question

A train travel same distance with the speed of 30km/h and returns with a speed of 45km/h calculate average speed

Answer 1

Hi friend, let d/2 be the distance covered by train with a speed of 30kmph in t1 hours

→t1=d/60

it covers d/2 distance with a speed of 45km/h in t2 hours

→t2=d/90

average speed = total distance/total time

=d/(t1+t2)

=1/(1/60+1/90)

=1/(3+2)/180

=180/5=36kmph

I hope this will help u ;)

Answer 2

37.5 is the answer...