A man goes down stream with a boat to some destination and returns upstream to his original place in

M4maths Previous Puzzles

28 Aug 2018 Boats and Streams

A man goes down stream with a boat to some destination and returns upstream to his original place in 15 hours. If the speed of the boat in still water and downstream are 10km/hr and 14km/hr respectively, the distance of the destination from the starting place in KMs is

OPtion

1) 48
2) 51
3) 45
4) 66
5) 67
6) 68
7) 69
8) 70
9) 63
10) None of these

Solution

Let the distance be D

Speed of boat in still water = 10
Speed of boat in down stream = 14
Speed of Stream = 14=10 = 4
Speed of boat in upstream = 10-4 = 6

Time Downstream + Time upstream = 15
=> D/14 + D/6 = 15
=> 10D = 630
=> D = 63
Option 9)

Correct Option: 9 Best Solution (7)