Aug 23, 2013

1305:TSD : Two Pools

A and B are the two opposite ends of a swimming pool and the distance between them is
420 metres. Ankur and Manu start swimming towards each other at the same time from A and B,
with speeds in the ratio 5 : 9 respectively. As soon as any of them reaches an end, he turns back
and starts swimming towards the other end. At what distance (in metres) from A will they meet when
Manu is in his 13th round? Note: A to B is considered one round and B to A another round.

(a) 405 (b) 330 (c) 240 (d) 280


Answer

By the time Manu completes 12 rounds, Ankur will complete × = 5/9 *12 = 6 -2/3 rounds. At this point in time Ankur is moving towards B and is 280 metres away from A whereas Manu is at B.
They will meet at a distance of

9 * (420 -280)/ 5+ 9 = 90 metres from B. This point will be at a distance of 420 – 90 = 330 metres from A.

Answer : B

From Eduventures _Puneet Singh

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