Billy has a collection of baseball cards that he has separated into two different value categories. His common cards
are worth $0.50 each, while his premium cards are worth $1.00 each. Together, Billy's entire baseball card collection
of 124 cards is worth $81.50.
Which of the following systems of equations models Billy's baseball card collection?

Bella want to know what the students at her school think of her show. which is the best group to survey to find this information a. go to the mall and ask all of the students she recognizes from school b. ask her viewers to call in durning an episode of the show c. get a list of students at her school from the office and use a random number generator to pick 30 of them d. get a list of students at her school from the office and pick the first 30 students on the list