Question

A motorboat averages 20 miles per hour (mph) in still water. It takes the boat the same amount of time to travel 3 miles with the current as it does to travel 2 miles against the current. What is the current's rate in mph?

Answer 1

4 mph

Explanation:

Let :

Boat speed = 20 mph

speed of current = x mph

Distance against current = 2 miles

Distance with current = 3 miles

speed against current will be ; 20 - x

speed with current will be ; 20 + x

Time =distance / speed against time against = time with current

Solving Mathematically ;

2/(20-x )=3/(20 +x)

2(20+x )= 3( 20-x )

40+2x = 60-3x

3x +2x=20

5x=20

x = 20 / 5

x = 4 mph

Speed of current = 4 mph