Please answer this question step by step if possible

The manageriof a restaurant found that the cost to produce 100 cups of coffee per day is $55, while the cost to produce 160 cups per day is $70. Assume cost is a linear function of x, the number of cups of coffee produced per day. They sell the cups of coffee for $0.75 apiece. 4) How many cups of coffee must the restaurant sell per day in order to break-even? a) 60 cups b) 30 cups c) 40 cups d) 120 cups e) 15 cups