problems

1) Train A starts from X at 12:00 p.m & reach at Y on 2:30 p.m & train B starts from Y at 12:15 and reach at X on 2:15 so,when both trains crosses each other?

2) Two trains are travelling from point A to point B such that the speed of first train is 65kmps and the speed of 2train is 29km/hr.Where is the distance b/w A & B such that the slower train reached 5hrs late compared to the faster?

3) A man buys spirit at Rs 60 per litre, adds water to it and then sells it at Rs 75 per liter.What is the ratio of spirit to water if his profit in the sell is 37.5%?

4) A certain quantity of petrol is found to be adulterated to the extent of 10%. What proportion of the adulterated petrol should be replaced with the pure petrol to take the purity level to 98%?

5) Boat goes downstream from P to Q in 2hrs,upstrem in 6hrs and if speed of stream was 1/2 of boat in still water.Find distance PQ? ans:- 6 / 4 / 10 / none.

Try to give the explanations of every sum.