Operations Management help needed. please check your work, provide explanation if possible. if it's right I'll give you a like.

A recycling plant has just signed a contract to provide 2000 tons of recycled metal per week. The owner suspects he will need to speed up the process to fulfill the promised volume within the normal 40-hour work week. However, in the meantime he is willing to pay overtime to meet the contract. All stations have to be manned for safety reasons so as long as the plant is operating all works must be present. How many overtime hours will the plant be operating per week initially (Most nearly)? 8 hours/week 10.5 hours/week 13.3 hours/week 15 hours/week 18.3 hours/week