Customers Arrive at the Local Grocery Store Every 30 Seconds

Multiple Choice

Customers arrive at the local grocery store every 30 seconds on average.Thirty percent of these customers spend an average of 15 minutes shopping and purchase 10 items or less.These lucky customers go to the express line where they enjoy an average checkout time of 5 minutes.Customers that don't meet the express line criterion average 40 minutes in the store and go to checkout line #2 where they spend an average of 10 minutes checking out.How many people are shopping at any given time?

A) Less than or equal to 35
B) Greater than 35 but less than or equal to 70
C) Greater than 70 but less than or equal to 105
D) Greater than 105