Al and Betty want to create a playlist of songs for their drive back and forth to school. Since Al and Betty have different tastes in music, they decide to compromise by only playing Al’s favorite rap and Betty’s favorite pop music that they can both agree upon. Betty wants to include at least as many pop songs as rap songs. Al, in return, wants to include at least five rap songs. To provide enough variety to make the playlist interesting, they decide to include at least 20 songs altogether.

To create the playlist, Al and Betty will need to purchase the songs. They will have to pay $1.50 for each rap song and $1.00 for each pop song. How many of each type should they put on their playlist to minimize their cost?