# algebra

posted by on .

If sally can type a certain number of mailing labels in 6 hours and eric and sue working together can type the same number of mailing lables in 4 hours, find how long it takes eric alone to type the mailing labels.

• algebra - ,

Assume there are N labels.
Sally mails S labels/h
Eric labels E labels/h

6 S = N
4 S + 4 E = N
4S + 4 E = 6 S
2 S = 4 E
S = 2 E
E is half as fast as S, and woul;d take 12 hours alone.

• algebra - ,

thanks drwls!
are you available to answer one right now?

• algebra - ,

Alex can run 5 miles per hour on levelground on a still day. One windy day he runs 11 miles with the wind, and in the same amount of time runs 4 miles against the wind. What is the rate of the wind?

• algebra - ,

Read the second bullet point on the first page, in the bold and italics, at the end of the second sentence.

I seriously, seriously hope you weren't dumb enough to use your real first name. Mine definitely isn't Serj.

time = distance/rate and you set the rate up as (5+x) and (5-x) where x is the wind rate. The distance is obvious. solve for x.