Question

Two stations m and b are 110 km apart on a straight line. one train starts from a at 7

a.m. and travels towards b at 20 kmph. another train starts from b at 8

a.m. and travels towards m at a speed of 25 kmph. at what time will they meet?]]

Answer 1

look , when train B begins at 8 train a has travelled 20km
so distance betwween A and B at 8am is 90kms
now since they are travelling towards each other there relative velocity becomes v1+v2=45kmph
it will take 2 hrs (90/45) for them to meet
so they meet at 10 am