## A boat going upstream on The River averages 4 mph. Going downstream, the boat averages 9 mph. Find the speed of the current and the speed of

Question

A boat going upstream on The River averages 4 mph. Going downstream, the boat averages 9 mph. Find the speed of the current and the speed of boat in still water.
The speed of the boat in still water is
mph
The speed of the current is
mph

in progress 0
1 hour 2021-09-13T00:24:49+00:00 1 Answer 0

1. Answer: The speed of the boat in still water is 6.5 mph.

The speed of the current is 2.5 mph

Step-by-step explanation:

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

Let y represent the speed of the current.

A boat going upstream on The River averages 4 mph. Assuming it travelled against the current while going upstream, its total speed would be (x – y) mph. It means that

x – y = 4- – – – – – – – – – – -1

Going downstream, the boat averages 9 mph. Assuming it travelled with the current while going upstream, its total speed would be (x + y) mph. It means that

x + y = 9- – – – – – – – – – – -2

2x = 13

x = 13/2

x = 6.5 mph

Substituting x = 6.5 into equation 1, it becomes

6.5 – y = 4

y = 6.5 – 4

y = 2.5 mph