If a person rows to this favorite fishing spot 17 miles downstream in the same amount of the time he rows 1 mile upstream and if the current is 8mph, find how long it takes him to cover 18 miles

We use the formula : Displacement = Average Velocity * Time;

17 = (v + 8) * t;

1 = (v - 8) * t;

where v = the velocity of the boat; t is the time from expression " ... in the same amount of the time he rows ... "

Then 17 / 1 = (v + 8) / (v - 8);

v + 8 = 17 (v - 8);

v + 8 = 17v - 136;

144 = 16v;

v = 144 / 16;

v = 9 mph;

18 = 9 * x;

x = 18 / 9;

x = 2 hours;

The answer is 2 hours;