Suppose that the capacity of the regular machines has been increased to 65,000 hours. Pendleton has been approached by Carter Corporation to supply 20,000 units of another cutting tool, S3, for $120 per unit. Pendleton must either accept the order for all 20,000 units or reject it totally. S3 is exactly like R3 except that its variable manufacturing cost is $70 per unit. (It takes one hour to produce one unit of S3 on the regular machine, and variable marketing cost equals $15 per unit.) What product mix should Pendleton choose to maximize operating income? Show your calculations.