The Acme Chemical Company has some employees who work in a p
     The Acme Chemical Company has some employees who work in a production plant and some who work in a sales office. The plant workers get paid every Friday; however, the office workers get paid for every fifth sale that they make.  The plant workers are paid on a ___ schedule, whereas the office workers are paid on a ___ schedule.  A) variable ratio; fixed interval  B) variable interval; variable ratio  C) fixed interval; fixed ratio  D) fixed ratio; variable interval 
  
  Solution
Answer : C : Fixed interval (every friday) and fixed ratio (on every fifth sale)

