A firm has the production functionQ = KL²,where K is the amount of capital and L is the amount of Labor. The cost per unit of K is 3 and the cost per unit of L is 2.The optimal number of labor to produce 72units is:

1. 4
2. 6
3. 7
4. 9

Suppose the firm 1's supply curve is Q= 2P + 20 and firm's 2 supply curve is Q = 2P - 10. What's the function that describe the total market supply when P is between 4 and 5?

1. Q=4P - 10
2. P = 1/2Q -10
3. P = 1/2Q + 5
4. Q =(4P +10)/2