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.
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.
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.
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.