Question

The speed of the boat going with a current is 20 mph. When the boat goes against the current, the speed is 16 mph. Find the speed of the boat in still water and the speed of the current.

Answer 1

The speed of the boat in still water is 18 mph.

The speed of the current is 2 mph

Explanation:

Let x represent the speed of the boat in still water.

Let y represent the speed of the current.

When the boat goes against the current, the speed is 16 mph. Assuming it traveled against the current while going upstream, its total speed would be (x - y) mph. It means that

x - y = 16 (equation 1)

Going downstream, the boat averages 20 mph. Assuming it traveled with the current, its total speed would be (x + y) mph. It means that

x + y = 20 (equation 2)

Adding both equations, it becomes

2x = 36

x = 36/2

x = 18 mph

Substituting x = 18 into equation 1, it becomes

18 - y = 16

y = 18 - 16

y = 2 mph