Question

A boat can go 119 mph in still water. it takes as long to go 320 miles upstream as it does to go downstream 360 miles how fast is the current?

Answer 1

Speed of current is 7 mph

Explanation:

Let v be speed of current,

We have speed of boat = 119 mph

Upstream speed = 119 - v

Downstream speed = 119 + v

Time for upstream 320 miles = Time for downstream 360 miles

$\frac{320}{119-v}=\frac{360}{119+v}\\\\\frac{8}{119-v}=\frac{9}{119+v}\\\\17v=119\\\\v=7mph$

Speed of current is 7 mph