A Government Agency Is Having Problems with Personal Telephone Calls

Multiple Choice

A government agency is having problems with personal telephone calls made during working hours.Because each minute of a personal call costs the agency $0.50 in wasted wages,it has decided to hire operators to monitor calls.The agency wants to hire the number of operators that will maximize the net benefit of hiring operators to monitor calls. $\begin{array}{c}\begin{array}{c}\text {Number of}\\\text { operators}\\0\\1\\2\\3\\4\\5\\\end{array}\begin{array}{c}\text {Minutes of personal}\\\text { calls(per week) }\\3900\\2300\\1300\\600\\100\\0\\\end{array}\end{array}$
Based on the above information,if operators receive $400 a week,what is the lowest possible total cost of personal calls?

A) $ 650
B) $ 800
C) $1450
D) $1500