EXPLANATION
Since the speed of the boat is 12 mph, and it takes 2 hours to travel 16 miles, we can affirm that the speed of the current is the difference between the speed of the boat and the given time.
[tex]\text{Total}_{\text{speed}}=\frac{16\text{ miles}}{2\text{ hours}}=8\text{mph}[/tex]The difference between both velocities is 12mph - 8 mph = 4 mph
In conclusion, the speed of the current is 4mph
