college algebra word problems

label Mathematics
account_circle Unassigned
schedule 1 Day
account_balance_wallet $5

i am stuck on the following problem. here is a pic of the problem

http://imgur.com/TSsIqiI

any help would be appreciated

Dec 3rd, 2014

We know the distance formula; d = rt
where, d = distance; r = rate; t = time
Solving for time (t) => t = d/r

Let x = speed of current
t1 =Time going downstream = 120/(18+x)
t2 =Time going upstream = 24/(18-x)

Since the boat travels 120 miles downstream in the same time it travels 8 miles upstream we can set t1 and t2 equal to each other and solve for x.
120/(18+x) = 24/(18-x) 
Cross mulitply and we have: 120(18-x) = 24(18+x)
Simplify by dividing both sides by 24:  5(18-x) = (18+x)
90 - 5x = 18 + x => 90 = 18 + 6x => 72 = 6x => x =12
Therefore, Speed of current = 12 mph

Hope this helps, and if it does don't forget to "best" my answer! :)

Dec 3rd, 2014

Studypool's Notebank makes it easy to buy and sell old notes, study guides, reviews, etc.
Click to visit
The Notebank
...
Dec 3rd, 2014
...
Dec 3rd, 2014
Jun 28th, 2017
check_circle
Mark as Final Answer
check_circle
Unmark as Final Answer
check_circle
Final Answer

Secure Information

Content will be erased after question is completed.

check_circle
Final Answer