The speed of boat in still water is 11km/hr it can go 12km upstream and return down stream in 2hr 45min. Find the speed of the stream
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Let the speed of the stream be "x km/ hr.".
Speed of boat in still water = 11 km/ hr.
Therefore, speed of boat upstream = 11 - x
speed of boat downstream = 11 + x
A.T.Q., 12 / 11 - x + 12 / 11 + x = 2 3/4
===> 12 ( 1/ 11 -x + 1/ 11 + x ) = 11 / 4
===> 22 / 121 - x2 = 11 / 4*12
===> 22/ 121 - x2 = 11 / 48
===> 1331 - 11 x2 = 1056
===> 11 x2 = 275
===> x2 = 25
===> x = +5 or -5
As speed can't be negative, x not equal to -5.
Therefore, Speed of stream = x = 5 km / hr.
Hope it helps !
Speed of boat in still water = 11 km/ hr.
Therefore, speed of boat upstream = 11 - x
speed of boat downstream = 11 + x
A.T.Q., 12 / 11 - x + 12 / 11 + x = 2 3/4
===> 12 ( 1/ 11 -x + 1/ 11 + x ) = 11 / 4
===> 22 / 121 - x2 = 11 / 4*12
===> 22/ 121 - x2 = 11 / 48
===> 1331 - 11 x2 = 1056
===> 11 x2 = 275
===> x2 = 25
===> x = +5 or -5
As speed can't be negative, x not equal to -5.
Therefore, Speed of stream = x = 5 km / hr.
Hope it helps !
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