Question

A train travels some distance with a speed of 30km/h and returns with a speed of 45km/h .Calculate the average speed of the train​

Answer 1

Let the total distance be d,

Let the time for going be T1,

Let the timing for coming back be T2,

So according to the question,

We know,

s=d/t

According to the question,

30 = (d/2)/T1..... (1)

45 = (d/2)/T2.....(2)

We have,

Average speed = total distance/(total time taken)

So,

= d/(T1+T2)

= d/(d/60+d/90)

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

= 180/5

= 36 km/hr

Answer 2

Holaaa Mate

Answer:

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