One train leaves Los Vegas at 15 mph heading for New York. Another train leaves from New York at 20 mph heading for Los Vegas on the same track. The distance between Los Vegas and New York is about 5000 km. If a bird, flying at 25 mph, leaves from Los Vegas at the same time as the train and flies back and forth between the two trains until they collide, how far will the bird have travelled?

There are sequence of 5 Church separated by 5 rivers,
Sequence is Church, River, Church, River…………
A man has to put equal number of flowers on every Church but the catch is as he crossed the river, remaining flowers will be doubled (2 times)

How many flowers should a man carry with him before entering into first Church so that till last river he has left with nothing ?