Expert: Paul Klarreich - 9/2/2009

Question
When i did this problem i got the answer 33n/3000n which was wrong.

the problem is
A College Algebra class of 33 students could do n problems in x hours. If 3 students were absent, how long would it take to do 100 problems?

i started with n/33n x 30 x t = 100

Answer
Questioner: drew
Country: United States
Category: Advanced Math
Private: No
Subject: abstract rate
Question: When i did this problem i got the answer 33n/3000n which was wrong.

the problem is
A College Algebra class of 33 students could do n problems in x hours. If 3 students were absent, how long would it take to do 100 problems?

i started with n/33n x 30 x t = 100
...........................................
That is not how you start a verbal problem.  You start with some thinking:

If 33 students do n problems, then  1 student does  n/33 problems in x hours.
Then 1 student does n/33x in each hour and that is a student's rate of problem-solving, which is in problems per student-hour.

Now you should be OK.