A river cruise boat sailed 80 miles down the Mississippi River for 4 hours. It took 5 hours to return. Find the rate of the cruise boat in still water and the rate of the current.

Rate of Cruise Boat is 18 miles per hour and Rate of Current is 2 miles per hour

Step-by-step explanation:

Speed of boat is "x"

speed of current is "c"

We also know D = RT

Where D is distance, R is rate, T is time

For Downstream:

D = RT

80 = (x + c) (4)

For Upstream:

80 = (x - c) (5)

The first equation becomes: 20 = x + c

The second equation becomes: 16 = x - c

We add both the equation:

20 = x + c

16 = x - c

36 = 2x

x = 18

And, 20 = x + c, 20 = 18 + c, c = 2

Rate of Cruise Boat is 18 miles per hour and Rate of Current is 2 miles per hour