A burger joint experiences demand at the rate of 150 customers/hr in its peak lunch time rush hour. They have the capacity based on their equipment and labor force to serve only 140 customers/hr. However, the quality of their burgers starts to decline if they exceed serving 120 customers/hr. a. What is their peak hour utilization not taking into account their quality issues? b. What is their peak hour utilization defined based on their best operating level?