Please Help, everything you need is in the pictures attached

Atelephone call center uses three customer service representatives (csrs) during the 8: 30 a.m. to 9: 00 a.m. time period. the standard service rate is 3.0 minutes per telephone call per csr. assuming a target labor utilization rate of 80 percent, how many calls can these three csrs handle during this half-hour period?