A manufacturing company spent $30,000 on a new conveyor belt. If the conveyor belt resulted in cost

Question:

A manufacturing company spent $30,000 on a new conveyor belt. If the conveyor belt resulted in cost savings of $4200 per year, the length of time it would take for the company to recover its investment at 8% per year is closest to:
(a) Less than 9 years
(b) 9 to 10 years
(c) 11 to 12 years
(d) Over 12 years