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put this solution on YOUR website!A man rowing at the rate of 5 km/hr in still water takes thrice as much time in going 40 km upstream as he takes in going same distance downstream. find the rate at which water is flowing.
:
Let x = the rate water is flowing
then
(5+x) = boat speed downstream
and
(5-x) = boat speed upstream
;
Let d = distance one way
;
write a time equation; Time =
:
upstream time = 3 times downstream time
= 3(
)
=
Cross multiply
d(5+x) = 3d(5-x)
:
divide both sides d and eliminate it:
5 + x = 3(5 - x)
;
5 + x = 15 - 3x
:
x + 3x = 15 - 5
:
4x = 10
x =
x = 2.5 km/hr is the rate of the current
:
:
Check solution by finding the distances, should be equal:
5 + 2.5 = 7.5
3(5 - 2.5) = 7.5
:
