SOLUTION: A boat makes a trip downstream in 3 hours. it makes the upstream trip in the same current in 4 hours. the speed of the boat in still water would've been 11.2 per hours. what is the

Question 956484: A boat makes a trip downstream in 3 hours. it makes the upstream trip in the same current in 4 hours. the speed of the boat in still water would've been 11.2 per hours. what is the speed of the current?
Answer by macston(5194) (Show Source): You can put this solution on YOUR website!
If the given speed of the boat in still water is 11.2 miles/hour:
r=rate of current
3hrs(11.2mph+r)=4hrs(11.2mph-r)
33.6miles+3r hrs=44.8 miles-4r hrs Subtract 33.6 miles from each side.
3r hrs=11.2 miles-4r hrs Add 4r hrs to each side
7r hrs=11.2 miles Divide each side by 7 hrs
r=11.2/7 mph=1.6 mph ANSWER The rate of the current was 1.6 mph.
CHECK:
3hrs(11.2mph+r)=4hrs(11.2mph-r)
3hrs(11.2mph+1.6mph)=4hrs(11.2mph-1.6mph)
3hrs(12.8mph)=4hrs(9.6mph)
38.4miles=38.4miles
RELATED QUESTIONS
A boat makes a 120-mile trip downstream in 3 hours but makes the return trip in 4 hours.... (answered by josmiceli)

A boat makes a trip downstream in 1 hour. It makes the upstream trip in the same current (answered by Cromlix)

A boat travels 180 miles in 5 hours downstream and makes the return trip in 6 hours. what (answered by derangoj)

A motorboat travels upstream in five hours and makes the return trip downstream in three... (answered by dabanfield)

a motor boat took 3 hours to make a downstream trip with a 4 mph current. The return trip (answered by mananth)

A boat takes a trip upriver against the current in 6 hours. Coming back down river, the... (answered by josmiceli)

A Mississippi riverboat travels 24 miles downstream in three hours and then makes the... (answered by stanbon)

A boat travels 500 miles downstream and back. The trip downstream took 25 hours. The trip (answered by mananth)

a boat traveled 420 miles downstream and 420 miles back upstream. the trip downstream... (answered by mananth)