what is the time between orders in working days if you were ordering EOQ

GROCERY STORE PROBLEM: A local grocery store faces demand for one of its items at a constant rate of 20,000 boxes per year. It costs them $5 to process an order and $0.50 per box per year to carry the item in stock. The stock is received three working days after an order is placed. Assume 250 working days in a year and no backordering. What is the time between orders (TBO) in working days if you were ordering EOQ? 0.317 7.9 12.9 0.0317