<PRE><B>Question 214353</B>
Let x=amount of time it would take 20 machines to produce 100 units

Now we know that if five machines can produce 20 units in 10 hours then one machine can produce 4 units in 10 hours or one machine can produce (4/10) units in one hour.  Soooo, it takes one machine-hour (one machine working one hour) to produce 4/10 units.  Then our equation to solve is:
(4/10)*20*x=100 simplifying we get:
8x=100
x=12 1/2  hours---amount of time it would take 20 machines to produce 100 units

ANOTHER WAY TO LOOK AT THE PROBLEM:
5 machines produce 20 units in 10 hours
5 machines produce 2 units in 1 hour
Then 20 machines produce 8 units in 1 hour

Hope this helps----ptaylor</PRE>