Answers

2014-12-03T19:53:27+05:30
let speed of boat= X mph
     sped of current=  Y mph          
As per question 3(X+Y)=72   
                   and 4(X-Y)=72
hence  3X+3Y=4X-4Y
         ⇒       X=7Y
Substituting value of X we get⇒ 24Y=72
                                            ⇒    Y=3
                                     and X=7×3=21
Speed of current is 3 mph and boat is 2 mph
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