A firm produces and sells goods in a perfectly competitive market.

The firm's cost depends on the quantity produced.

The total cost function is

The firm will produce a positive (>0) quantity if the market price is at least equal to its shut-down price.

What is this firm's shut-down price?

Question 9 options:

1)

Shut-down price less than $100

2)

Shut-down price at least $160 ($160 or more)

3)

Shut-down price at least $100 but less than $120

4)

Shut-down price at least $140 but less than $160

5)

Shut-down price at least $120 but less than $140