Your company manufactures two models of speakers, the Ultra Mini and the Big Stack. Demand for each depends partly on the price of the other. If one is expensive, then more people will buy the other. If p1 is the price of the Ultra Mini, and p2 is the price of the Big Stack, demand for the Ultra Mini is given by q1(p1, p2) = 100,000 − 400p1 + 10p2 where q1 represents the number of Ultra Minis that will be sold in a year. The demand for the Big Stack is given by q2(p1, p2) = 150,000 + 10p1 − 400p2. Find the prices for the Ultra Mini and the Big Stack that will maximize your total revenue.