6. The owner of Clear Interior Environments, purchased an air scrubber, HEPA vacuum, and other equipment for mold removal for $15,000 eight months ago. Net cash flows were S-2000 for each of the first 2 months, followed by $1000 per month for months 3 and 4. For the last 4 months, a contract generated a net S6000 per month. Julian sold the equipment yesterday for $3000 to a friend. Determine the no-return payback period.