Question

The speed of a boat in still water is 3 miles per hour. If the boat travels 5 miles downstream in the same amount of time it takes to travel 0.5 miles upstream, what is the speed of the current?

Answer 1

Explanation:

let the speed of stream=x mi/hr

then (3+x)t=5

and (3-x)t=0.5

or

3t+xt=5

3t-xt=0.5

add

6t=5.5

t=5.5/6 hr

(3+x)t=5

3+x=5/t=5×6/5.5=6/1.1

x=6/1.1-3=(6-3.3)/1.1

x=2.7/1.1 /approx 2.45 miles/hr