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A boat covers a certain distance downstream in 1 hour, while it comes back in 1.5 hour. If the speed of the stream be 3 km/hr. What is the speed of the boat in still water?

A boat covers a certain distance downstream in 1 hour, while it comes back in 1.5 hour. If the speed of the stream be 3 km/hr. What is the speed of the boat in still water? Correct Answer 15 km/hr

Let, the speed of the boat in still ater = x km/hr 1st ATQ , xx + 3 = 1⇒x = x + 3..(i) 2nd ATQ, xx - 3 = 1.5⇒x = 1.5x  - 4.5 ... (ii) From (i) and (ii) we havex + 3  = 1.5x  - 4.5 .... (ii) ⇒0.5x  = 7.5⇒x = 7.50.5⇒x = 755.'. x = 15 

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