The total completion time is 25 days. Task A is planned to take seven days. Task B is planned to take five days. Task C is planned to take eight days. The tasks have a serial relationship. Task A takes nine days to be completed instead of seven days. How much slack does the project have now that Task A is finished

Which of the following statements is (are) true? i. free entry to a perfectly competitive industry results in the industry's firms earning zero economic profit in the long run, except for the most efficient producers, who may earn economic rent. ii. in a perfectly competitive market, long-run equilibrium is characterized by lmc < p < latc. iii. if a competitive industry is in long-run equilibrium, a decrease in demand causes firms to earn negative profit because the market price will fall below average total cost.