reasoning Maths Puzzle

A person crosses a river on a paddle boat.
He took 4 hours while paddling against the water flow
and 3 hours while paddling in the direction of the water flow.
On still waters, how long would he take?

Read Solution (Total 3)

let, the velocity of the boat be u,and velocity of current be v. then
u+v = 3&u-v = 4 solving this we get ,
u = 3.5
8 years agoHelpfull: Yes(0) No(1)

4+3=7
7/2=3.5
8 years agoHelpfull: Yes(0) No(1)
Answer 3.4 hrs

Let the distance be 12 kms.
Given, Time for downstream,U = 3hrs
Time for Upstream, V = 4hrs
So, U = 4km/hr and V = 3km/hr.
Speed of the boat in still water, a = 1/2(U+V) = 1/2(4+3) = 3.5km/hr
Now, time taken for the boat in still water is = 12/3.5 = 3.4hrs.
7 years agoHelpfull: Yes(0) No(0)

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