MHB Rower Goes Upstream 2.8 km in 48 Minutes

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A rower travels upstream at 6 km/hand back to the starting place at 10 km/h.The total
journeytakes 48 minutes. How far upstream did the rower go?

My approach is to use speed = distance / time

The total time =upstream time + downstream time

In hours

0.75 = x/6 + x/10

solving I get 45 = 10x + 6x

x = 2.8 km


 
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Hmmm...well 48 minutes is 4/5 of an hour, not 3/4. :D
 

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