Question 431177: It takes 3 hours for 2 cement mixers to mix a certain amount. How long would it take 5 cement mixers to do the job? Answer by Edwin McCravy(20054) (Show Source): You can put this solution on YOUR website! It takes 3 hours for 2 cement mixers to mix a certain amount. How long would it take 5 cement mixers to do the job?
Since it takes 3 hours for 2 cement mixers,
it would takes 6 hours for 1 cement mixer. Then
5 cement mixers could do it in 1/5 the time it takes
1 cement mixer to do it, so,
1/5 of 6 hours is
1 and 1/5 hours which is 1 hour and 12 minutes.
Edwin