Aptitude Questions and Answers
Find the speed of the boat in still water, if a boat covers a certain distance upstream in 2 hours, while it comes back in 1`1/2` hours. If the speed of the stream be 3 kmph.
Let the speed of the boat in still water be x kmph. Then,
Speed downstream = (x + 3) kmph,
Speed upstream = (x - 3)kmph.
`(x - 3) * 2 = (x + 3) * 3/2`
4x - 12 = 3x + 9
x = 21kmph.
Mayur takes thrice as long to row a distance against the stream as to row the same distance in favor of the stream. The ratio of the speed of the boat(in still water) and the stream is:
Let speed in still water be x and speed of stream be y
(Speed in still water) : (Speed of stream)=x:y
Distance is same, then time taken downstream is t, and time taken to travel upstream is 3t.
`[(x+y) / t] = [(x-y) / (3t)]`
2x = 4y
`x/y = 4/2 = 2/1`
x:y = 2:1