Question

A fisherman can row upstream at 4mph and downstream at 6mph. He started rowing upstream until he got tired and then started downstream to his start point. How far did the fisherman row if the trip took 3 hours?

Answer 1

Answer:

Fisherman traveled 14.4 miles.

Step-by-step explanation:

A fisherman's downstream speed = 6 mph

and upstream speed = 4 mph

Let the fisherman traveled x miles he travels upstream.

Time spent in travelling x miles = $\frac{x}{4}$ hours [Since time = $\frac{\text{distance}}{\text{speed}}$]

Similarly when fisherman covers x miles down stream

Time spent in x miles = $\frac{x}{6}$ hours

Now total time in going upstream and downstream is 3 hours then

$\frac{x}{4}+\frac{x}{6}=3$

x$(\frac{3+2}{12})=3$

$(\frac{5x}{12})=3$

5x = 12×3

5x = 36

x = $\frac{36}{5}=7.2$ miles.

Since fisherman has traveled 2x distance so the answer will be 14.4 miles

Therefore, fisherman traveled 14.4 miles.

Answer 2

Total time = upstream time + downstream time
he rowed the same distance both ways.
upstream time = D/4
downstream time = D/6
total time = D/4 + D/6 = 3D/12 + 2D/12 = 5D/12 = 3 hours
D = 3*12/5 = 36/5 or 7.2 miles
where D is the one-way distance. The total distance he rowed is 2*D = 72/5 or 14.4 miles

Answer 3

3.2 mph..............