Cost, revenue, and profit rates. Suppose that for a com- pany manufacturing calculators, the cost, revenue, and profit equations are given by C = 90,000 + 30x R = 300x - 30 P=R-C where the production output in 1 week is x calculators. If production is increasing at a rate of 500 calculators per week when production output is 6,000 calculators, find the rate of increase (decrease) in (A) Cost (B) Revenue (C) Profit Cost, revenue, and profit rates. Repeat Problem 33 for C=72,000 + 60x R = 200x P=R-C 30 where production is increasing at a rate of 500 calculators per