Question

two trains a and b, each of length 250 m are moving on a parallel track at 90 km/h and 72 km/h respectively in same direction.intially train a is 1 km behind train b .the time after which train a completely overtake train b is​​

Answer 1

So here we have to take difference in speeds as trains are moving in same direction

which in 90 - 72 = 18 km/hr = 5 m/s

Now to over take train b , a has to travel 1 km plus the sum of lengths i.e 1000 + 250 + 250 = 1500 m

so the time required 1500 / 5 = 300 seconds

which is equivalent to 5 mins