10 machines can do it in 3 days
6 machines : 5 days
3 machines : 10 days (half the amount of machines means double the work per machine so double to time)
1 machine : 30 days (now I know the time it takes for 1 machine to complete the task I can work out how long it would take 10 to)
So if I multiply 1 by 10, I divide 30 by 10 giving my the ratio 10 machines : 3 days
