Sales revenue was $57,102, Accounts receivable increased by 17,516. What was the cash collected from customers

Bakery has bought 250 pounds of muffin dough. they want to make waffles or muffins in half-dozen packs out of it. half a dozen of muffins requires 1 lb of dough and a pack of waffles uses 3/4 lb of dough. it take bakers 6 minutes to make a half-dozen of waffles and 3 minutes to make a half-dozen of muffins. their profit will be $1.50 on each pack of waffles and $2.00 on each pack of muffins. how many of each should they make to maximize profit, if they have just 20 hours to do everything?