CoolT produces both cool and very cool tshirts in a ratio of
     Cool-T produces both cool and very cool t-shirts in a ratio of 2:3. Its costs are C(q_1,q_2) = 3,200 + 0.1q_1 + 2q^2_1 + 0.2q_2, where q_1 is the number of cool t-shirts and q_2 is the number of very cool t-shirts. Calculate the ray average cost (RAC). 
  
  Solution
RAC(q) = C(0.4q, 0.6q)/q = (3200 + 0.04q + 0.32q + 0.12q)/q = 3200/q + 0.48

