On a weekend outing, Bernard rents a motorboat for 6 hours to travel down the river

E

Emily1

Active member
Joined
May 13, 2008
Messages
1,320
Reaction score
0
Points
36
and back. The rental opera? On a weekend outing, Bernard rents a motorboat for 6 hours to travel down the river and back. The rental operator tells him to go for 2 hours downstream, leaving 4 hours to return upstream. If the river current flows at the speed of 4 mph, how fast much Bernard travel in order to return in 6 hours?
 
Let his speed be S

In 2 hours he travels 2 * (S + 4) downstream

In 4 hours he travels 4 * (S - 4) upstream.

Since he must return to his start point, we know that downstream distance = upstream distance so,
2 * (S + 4) = 4 * (S - 4)
 
Back
Top