Jim and Fred Are the Only Two Cashiers Employed at a Retail

Multiple Choice

Jim and Fred are the only two cashiers employed at a retail store.Each of them works the same 40 hours per week and each can check out 30 customers per hour by manually entering the price of each product purchased into the cash register.The store owner replaces the old cash registers with new ones that automatically scan product prices into the register.With the new registers,Jim and Fred can each check out 60 customers per hour.Their average labour productivity,as a team,was ________ customers per hour,before the new cash registers were introduced,and _________ customers per hour after the new machines were installed.

A) 30;60
B) 30;120
C) 60;120
D) 1,200;2,400
E) 2,400;4,800