Full tilt Company produces and sells two garden tiller products with the following data for each product. Nine Inch Tiller Six Inch Tiller Demand (units) per day 145 100 Per unit amounts: Selling price $120 $105 Direct materials $63 $60 Direct labor cost $12 $10 Direct labor time 15 min. 10 min. Full tilt Company employs four workers to manufacture the tiller products. Employees receive time-off equal to one hour for lunch and breaks in the regular eight-hour workday and a 40-hour workweek. 

a. Which product is the direct labor constraint at Tiller Company? Show supporting calculations.

b. Calculate the throughput margin per labor minute for each product. 

c. Given the labor constraint on production how many units of each product (i.e., product mix) should Full tilt Co. product to maximize Operating Income? Show calculations to support your answer