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The speed of a river current is 3 km/h. A boat takes the same time to travel 12 km upstream as it does to travel 14 km downstream. What will be the speed of the boat upstream? * |
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Answer» 39km/h ans.Step-by-step explanation:SOLUTION:LET US ASSUME THAT THE REQUIRED SPEED OF THE BOAT IN STILL WATER IS X KM/H.NOW,THE SPEED OF A RIVER CURRENT IS 3 KM/HSO,WHEN THIS BOAT TRAVELS DOWNSTREAM-NET SPEED DOWNSTREAM => (X+3) KM/H.SO,WHEN THIS BOAT TRAVELS UPSTREAM-NET SPEED UPSTREAM => (X-3) KM/H.NOW,SPEED = DISTANCE / TIME.THE BOAT TAKES THE SAME TIME TO TRAVEL TO 12KM UPSTREAM.LET THE TIME TAKEN TO COVER THIS DISTANCE BE T HOURS.(X-3) = 12/T ........ {1}THE BOAT TAKES THE SAME TIME TO TRAVEL 14 KM DOWNSTREAM. (X+3) = 14/T ....... {2}NOW, DIVIDE EQUATION 1 BY EQUATION 2.[X-3] [X+3] = [6/7]6 (X+3) = 7 (X-3)6X + 18 = 7X - 216X - 7X = -21 -18 - X = -39:. X = 39 KM/HHENCE, THE REQUIRED SPEED OF THE BOAT IN STILL WATER IS 39 KM/H.HOPE IT'S HELPS YOU...PLEASE MARK ME AS A BRAINLIEST ☺ |
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