Upstream and Downstream

A fisherman can row upstream at 4 mph and downstream at 6 mph. He started rowing upstream until he got tired and then rowed downstream to his starting point. How far did the fisherman row if the entire trip took 5 ​hours?

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distance = rate x time
or 
d = rt

However, the information given includes the rates and the total time of the trip.
So, solve the formula, d = rt for t (time).  You'll see why in a little bit!

d = rt {distance, rate, time formula}
t = d/r  {solved for t.....time equals distance divided by rate}

Now, apply that to what is given to you.

d = distance the point he got tired {which is the same distance upstream and downstream}

Remember, t = d/r  {the time is the distance divided by the rate}
d/4 + d/6 = 5  {the two times are d/4 and d/6....distance divided by rate}
3d + 2d = 60   {multiplied entire equation by 12 to eliminate fractions}
5d = 60   {combined like terms}
d = 12  {divided by 5}

distance upstream was 12
distance downstream was 12   {same as upstream}

Total distance = 24 miles

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