A son and father goes for boating in river upstream . After rowing for 1 mile son notices the hat of his father falling in the river. After 5 min. he tells his father that his hat has fallen. So they turn around and are able to pick the hat at the point from where they began boating after 5 min. Find out the speed of river.

2 Answers on this Question

1. 6 miles per hour…….
   actually hat fell when they were 1 mile away from starting
   and total time hat takes to travel to the starting point is
   10 minutes ( 5 + 5 ).so, 1 miles per 10 minutes thats why 6
   miles per hour

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2. Cap fell here
   A————–>B—————–>C Upstream——–>
   1mile
   —–5 min——–
   A<-----<<-------B<--------<<------C <<------Downstream ---------------5 min--------------- cap reached here From B to A total time taken by cap to reach at A =5+5 =10 min (B-->C–C–>B–>A)
   Total distance covered by capto reach frm B to A =1 mile (with speed of river)
   so speed of river =1 mile/ 10 min
   = 1/(10/60)hr
   =6 mile/hr Ans

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