SOLUTION: six students were given 20 minutes to clean up the classroom after an eraser fight. They were angry and named 3 other accomplices. The principal added the accomplices to the cleanu

Algebra ->  Equations -> SOLUTION: six students were given 20 minutes to clean up the classroom after an eraser fight. They were angry and named 3 other accomplices. The principal added the accomplices to the cleanu      Log On


   

Question 844770: six students were given 20 minutes to clean up the classroom after an eraser fight. They were angry and named 3 other accomplices. The principal added the accomplices to the cleanup crew and changed the time limit. How much time did she give them to complete the job?
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
First find the one-student work rate. The 1 job is, "clean up the classroom".

six students needing 20 minutes means that 1 student needs 6%2A20=120 minutes if working alone. This rate is 1%2F120 job/minute.

The uniform rate equation for n number of students is highlight%28n%281%2F120%29t=1%29 for doing ONE job.

n=6%2B3=highlight_green%289%29 students to do the job.
t=120%2Fn
t=120%2F9
highlight%28t=13%261%2F3%29 minutes


Thirteen minutes 20 seconds