Answer:
22 hours
Explanation:
Old machine produces 36 widgets in 9 hours. The number of widgets produced in an hour can be determined as;
In 1 hour =
= 4 widgets
New machine can produce 40 widgets in 8 hours. The umber of widgets produced in an hour can be determined as;
In 1 hour =
= 5 widgets
Thus, let the time required by old machine be represented by s, and that of new machine by y. Working together we have;
4x + 5y = 100
(4 * 10) + (5 * 12) = 100
Thus the old machine would work for 10 hours, while the new machine would work for 12 hours to produce 100 widgets.
Working together, it would take both machines 22 hours.