Structure of variable cost TVC(Q)

Q1. Suppose each firm operating in a perfectly competitive market structure has a total variable cost TVC(Q) = 40Q + 0.5Q2. Each firm’s fixed costs are equal to 50.
a. Determine the price below which the firm will not produce any output in the short run.
b. If there are 12 identical firms in this industry and the market demand curve is given by QD = 360 − 2P, what is the short-run equilibrium price?
Q2. If the price elasticity of demand is estimated to be -2, and the firm faces a constant marginal cost of $1, what price will maximize profits
Q3. If the price elasticity of demand is estimated to be -2, and the firm faces a constant marginal cost of $1, what price will maximize profits