Question

The Epson workforce G7-1500 takes twice the time required by the Epson Workforce Pro GT-S50 to scan the manuscript for a book. If, working together, the twoo machines can complete the job in 5 min, how long would it take each machine, working alone, to scan the manuscript?

Answer 1

Let t be the time in minutes for the GT-S50 to scan the manuscript, working alone.
Then the G7-1500 will take 2t minutes to scan the manuscript, working alone.
If both machines work together for 1 minute they will scan 1/5 of the manuscript.
$\frac{1}{t} + \frac{1}{2t} = \frac{1}{5}$
$\frac{3}{2t} = \frac{1}{5}$
2t = 15
t = 7.5
When working alone, the machines will take the following times to scan the manuscript:
G7-1500: 15 minutes,    GT-S50: 7.5 minutes.