SOLUTION: john completed 20 problems in 12 minutes.At this rate, how long will it take him to complete the remaining 7 problems?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: john completed 20 problems in 12 minutes.At this rate, how long will it take him to complete the remaining 7 problems?      Log On


   

Question 350464: john completed 20 problems in 12 minutes.At this rate, how long will it take him to complete the remaining 7 problems?
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
20 problems 12 minutes
7 problems - ?
direct proprtion
7/20*12
=21/5
=4.2 minutes