The Accompanying Table Describes the Relationship Between the Number of Workers

Multiple Choice

The accompanying table describes the relationship between the number of workers hired by a call center each hour and the number of calls the call center can make each hour. The call center has only 1 telephone. The telephone costs the firm $5/hour (regardless of how many calls are made) , and each worker is paid $10 per hour.  
What is the total cost of making 6 calls an hour?

A) $30
B) $40
C) $60
D) $65