# A boat takes 9 hrs to travel from A to B upstream. If the river current is 3 km/hr, how long will it take to travel downstream between B and A ?

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by sachusoman

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by sachusoman

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simplify, divide by 9s - 3 = 20s = 20 + 3s = 23 mph speed in still water:(s+3) = effective speed downstream (B to A)Let t = time required to go downstreamt(23 + 3 ) = 18026t = 180t = 180/26t = 6.923 hrs to go downstream (B to A)

we get 100 = 9(x-3)

x = 100/9 + 3

substituting in 100 = y(x+3)

we get y = 900/154 = 450/77...

it will tke around 5.8 hours

thanks for reading