Problem 3 [ 25 Marks] A gadget company produces a specific type of gadget. The function D = 64 -0.42x gives the demand function for making x gadgets. If the fixed cost is £ 390 and the variable cost is £ 24, a. find: (i) the total cost function. (ii) the revenue function. (iii) the profit function. (iv) the breakeven points.