Aboat on a river travels downstream between two points, 20 mi apart, in one hour. the return trip against the current takes 2 1/ 2 hours (2hours and a half). what is the boat's speed (in still water)? b) how fast does the current in the river flow?

The speed of boat in still water is 14 miles per hour.

The speed of current is 6 miles per hour.

Step-by-step explanation:

Let v represent the speed of boat in still water and c represent speed of current.

We have been given that a boat on a river travels downstream between two points, 20 miles apart, in one hour.

The speed of boat downstream would speed of boat in still water plus speed of current that is .

The return trip against the current takes 2 1/ 2 hours. The speed of boat against current would speed of boat in still water minus speed of current that is .

Substituting our given values, we will get:

Adding both equations, we will get:

Therefore, the speed of boat in still water is 14 miles per hour.

To find the speed of the current in the river, we will substitute in equation (1) as:

Therefore, the speed of current is 6 miles per hour.

step-by-step explanation:

the answer is c: divide the arc's degree measure by 360°, then multiply by the circumference of the circle.