self Maths Puzzle

A man can row 30 km upstream and 44 downstream in 10 hours. It is also known that he can row 40km upstream and 55 km downstream in 13 hours. find the speed of the man in still water.

Read Solution (Total 1)

8km/hr

Let, rate upstream = x km/hr & rate downstream = y km/hr.
Then 40/x + 55/y = 13 ===(i)
and 30/x + 44/y = 10 ===(ii)
On solving (i) and (ii) we get
x=5 and y=11

Rate in still water = 1/2(11+5) Kmph = 8 kmph

Rate of current = 1/2(11-5) kmph = 3kmph
11 years agoHelpfull: Yes(4) No(0)

self Other Question

A boat sails downstream from point a to ponit b, which is 10 km away from a, and then returns to a. If the actual speed of the boat is 3 km/h, the trip from a to b takes 8 hours less then that of b to a. What must the actual speed of the boat for the trip from a to b to take exactly 100 minutes? M=f,r=k,w=g,s=?