The local television station is hosting a telethon for a local children’s charity. They have asked students and adult sponsors from high school clubs and organizations to volunteer to answer the pledge phones. The television station has the following guidelines for volunteers:
Because of the number of available phone lines, the station can handle no more than 20 total volunteers, which includes students as well as their adult sponsors.
There must be at least one adult sponsor for every 4 students who volunteer.
The group of volunteers must be able to process at least 120 calls per hour. From previous telethons, the station estimates that each high school student can process 9 calls per hour, but adult sponsors usually only handle about 4 calls per hour.