# Math Help - Dad can't solve

The word problem (designated as algebra) reads:

In his fishing boat, Nathan went downstream moving at one hour less than he went upstream the same distance. If the current is moving at 4 miles per hour, how fast can he travel on still water, if it took him three hours to make the upstream trip.

I double checked the wording of the problem.

2. Ok I think this is how you solve it:

$x$ = speed he can row
$c$ = speed of current
$T_u$ = Time to travel Upstream
$T_d$ = Time to travel Downstream
$D$ = Distance traveled

$Distance = Speed * Time$

$Speed = x \pm c$

Since the Distance is the same in both directions we have:

$T_u(x-c) = D = T_d(x+c)$

$T_u = 3$
$T_d = 2$

$3(x-4) = 2(x+4)$
$3x-12=2x+8$
$x=20$

So his speed is 20 miles per hour