A check-in desk at local car repair center has a capacity to serve 35 customers per work day. If the check-in desk had to utilize 60% of its capacity during a particular work day to fully satisfy expected demand, how much of a capacity cushion did the doctor's office have for that particular work day?
21 customers per work day
60 customers per work day
25 customers per work day
14 customers per work day
35 customers per work day