Kevin, Lakita, and Oscar work for a housekeeping company. Kevin can complete a regular job at a customer’s residence in 3 hours 50 minutes if he works alone. Lakita can complete the job in 4 hours 40 minutes if she works alone. One day Kevin, Lakita, and Oscar are all assigned to the job. Kevin and Lakita begin working at 1:00 P. M. Oscar arrives later and begins working at 1:20 P. M. They all complete the job at 2:20 P. M. How many minutes does it take Oscar to complete the job if he works alone? (Assume they all work at steady rates and their rates are not affected by either working alone or working together.)