# A boat can go 12 mph in calm water. If the boat goes down a river 45 miles and back up the river 45 miles it takes him 8 hours. What is the current of the river?

##### 1 Answer

Oct 22, 2015

Let's call the speed of the current

#### Explanation:

Downstream he will have a speed of

and upstream his speed will be

Now the downstream journey will take

And the upstream journey will take

So we get to the equation:

**Check your answer!**

Downstream:

Upstream: