SOLUTION: Question 1. One printing machine works twice as fast as another. When both machines are use, they can print a magazine in 3 h. How many hours would each machine require to do the

Question 161255: Question 1.
One printing machine works twice as fast as another. When both machines are use, they can print a magazine in 3 h. How many hours would each machine require to do the job alone.
Question 2. I takes my father 3 h to plow our cornfield with his new tractor. Using the old tractor it takes me 5 h. If we both plow for 1 hr before i go to school, how long will it take him to finish plowing.
Answer by scott8148(6628) (Show Source): You can put this solution on YOUR website!
1) each machine does some fraction of the job __ one machine's fraction is twice as large as the other machine's
__ 3/x+3/2x=1 __ multiplying by 2x __ 6+3=2x __ 4.5=x

2) in the hour before school, you plow 1/5 (3/15) of the field and your father plows 1/3 (5/15)
__ 7/15 remains to be plowed __ 7/15 * 3 = 21/15 __ 1 hr 24 min
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