A walks at 30 kmph and 30 hours after his start, B cycles after him at 45 kmph. How far from the start does B catch up with A?  Choose the correct option
A) 1200km  B) 1500km  C) 2000km  D) 2700km  E) 3600km
Suppose after x km from the start B catches up with A. Then, the difference in the time taken by A to cover x km and that taken by B to cover x km is 30 hours.   x/30 - x/45= 30   x = 2700 km   Answer is 2700km
<result>D</result>
A walks at 30 kmph and 30 hours after his start, B cycles after him at 45 kmph. How far from the start does B catch up with A?