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In a stream running at 4 km/hrs. a boat goes 6 km andreturns to the starting point in 2 hours. Find the speed ofthe boat in stationary water? |
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Answer» Let the speed in still water be x km/hr Then, [6/(x + 4)] + [6/(x - 4)] = 2 ⇒ 6[ x - 4 + x + 4] = 2(x2 - 16)⇒ x² - 6x - 16 = 0 ⇒ (x - 8) (x + 2) = 0 ∴ x = 8 km/hr |
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