R = rate of boat no current

C = rate of current

120 = 20(R-C)

120 = 5(R+C)

6 = (R-C)

24 = (R+C)

30 = +2R

15 = R

24-15 = -15 +15+C

9 = C

speed of tugboat is 15 mph, and the current is 9 mph.

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- Dec 9th 2012, 06:42 AMrcmangotugboat problem, check please.
R = rate of boat no current

C = rate of current

120 = 20(R-C)

120 = 5(R+C)

6 = (R-C)

24 = (R+C)

30 = +2R

15 = R

24-15 = -15 +15+C

9 = C

speed of tugboat is 15 mph, and the current is 9 mph. - Dec 9th 2012, 07:36 AMHallsofIvyRe: tugboat problem, check please.
It would help if you told us what the problem itself says! Are you saying that the boat goes

**upstream**120 miles in 20 hours and goes**downstream**120 miles in 5 hours?

It should be easy for you to check it yourself. If the boat has a normal speed of 15 mph and the current is 9 mph, the actual speed of the boat upstream, relative to the shore, is 15- 9= 6 mph. In 20 hours, the boat will have gone 6(20)= 120 miles. Downstream, the actual speed, relative to the shore, is 15+9= 24 mph. In 5 hours the boat will have gone 5(24)= 120 mi. Looks good. - Dec 9th 2012, 02:16 PMrcmangoRe: tugboat problem, check please.
If i was cgoing to get in trouble for asking for help, i probably wouldn't have asked, lol!

- Dec 9th 2012, 02:43 PMtopsquarkRe: tugboat problem, check please.
The problem was not in asking for help, but not actually posting a question. For instance you found values for R and C. They mean nothing on their own. What is the actual problem statement for this question?

Your post is a mystery. If you want help you're going to have to give more information.

-Dan