Find a Doctor (FaD) is a small startup that helps people find a physician that best meets their needs (location, insurance accepted, etc.). During a "slow" time for FaD, 7 staff members take calls from customers. On average, one call arrives every 5 minutes. On average, each staff member spends 20 minutes with each member. How long (in minutes) does a customer spend on average waiting on hold before he or she can start speaking to a representative?