The Westminster Widget Company has an old machine that can produce 50 widgets in five hours. Now they have purchased a new machine that can produce 30 widgets in two hours. Working together, how long will it take the two machines to produce 100 widgets?

Old machine: 50 widgets in 5 hours
New machine: 30 widgets in 2 hours

Old machine: 10 widgets per hour
New machine: 15 widgets per hour

Both machines: 25 widgets per hour

(100 widgets)/(25 widgets per hour) = 4 hours

Answer: It will take 4 hours.