a boat going upstream at 4 mph then travels downstream at 10 mph. what is the rate of the boat in still water

7 mph

Step-by-step explanation:

If b is the rate of the boat, and s is the rate of the stream, then:

b - s = 4

b + s = 10

Solve the system of equations with substitution or elimination. Using elimination, add the equations together:

2b = 14

b = 7

The boat's rate is 7 mph.