TV Reliability Problem

Engineer Doe has decided to own and operate a small TV station. He has the option of buying used or new subsystems to put the station together, and must decide what configuration will meet the required system reliability specifications to reach his target audience. He has promised his advertisers that their advertisements will reach 80% or more of the region within his area of operation. Students are asked to determine the reliability of the overall system. if Engineer Doe finds that this system will not meet the target audience he promised to his advertisers, what should he do?