Bruce Corporation makes four products in a single facility. These products have the following unit product costs: Products A B C D Direct materials $ 14.10 $ 10.00 $ 10.80 $ 10.40 Direct labor 19.20 27.20 33.40 40.20 Variable manufacturing overhead 4.10 2.50 2.40 3.00 Fixed manufacturing overhead 26.30 34.60 26.40 37.00 Unit product cost $ 63.70 $ 74.30 $ 73.00 $ 90.60 Additional data concerning these products are listed below. Products A B C D Grinding minutes per unit 3.60 5.10 4.10 3.20 Selling price per unit $ 75.90 $ 93.30 $ 87.20 $ 104.00 Variable selling cost per unit $ 2.00 $ 1.00 $ 3.10 $ 1.40 Monthly demand in units 3,800 3,800 2,800 3,000 The grinding machines are potentially the constraint in the production facility. A total of 53,500 minutes are available per month on these machines. Direct labor is a variable cost in this company. How many minutes of grinding machine time would be required to satisfy demand for all four products?