In the question, we are given the following parameters.
Step-by-step explanation
Using the given parameters, we will make the following assumptions.
Let x = speed of the boat,
Let y = speed of the current.
Recall,
Therefore we can create a simultaneous equation below.
A motorboat can go 8 miles downstream on a river in 20 minutes or 20/60hours.
Also, A motorboat can go 8 miles upstream on a river in 30 minutes or 30/60hours.
Therefore, if we subtract equation two from one we will then get the speed of the current.
Answer: The speed of the current is 4 miles per hour