Question

A fisherman can row upstream at 5mph and downstream at 10mph he started rowing upstream until he got tired and then rowed downstream to his starting point how far did the fisherman rown if the trip took 6 hrs

Answer 1

We have been given that the upstream speed is $5 mph$ and the down stream speed is $10mph$.

Let the fisherman traveled a distance of x miles.

The total time of the trip is 6 hours.

Relations between speed (s), time (t) and distance (d) is $s = \frac{d}{t}$

Hence, $t= \frac{d}{s}$

Time upstream +  time downstream = 6

$\frac{x}{5} +\frac{x}{10} =6$

lcm = 10

$\frac{2x+x}{10} =6$

=> $\frac{3x}{10} =6$

Cross multiplying, $3x= 60$

x = 20 miles .. Answer.