A boat covers 12 km upstream and 18 km downstream in 3 hours, while it covers 36 km upstream and 24 km downstream in n`6 1/2` hours. find the speed of the current.

Explanation

speed of boat=x km/h

speed of current=y km/h

Upstream speed=(x-y) km/h

Downstream speed=(x+y) km/h

`12/(x-y)+18/(x+y)=3-(1)`

`36/(x-y)+24/(x+y)=13/2-(2)`

multiplying equation 1 by 3 and subtracting equation 2

`54/(x+y)-24/(x+y)=5/2`

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