The music department needs to secure buses for a field trip. Listed below are the total of participants in each of the band, choir and orchestra. 60 students play in the band. 70 students sing in the choir. 50 students play in the orchestra. 12 students are in the band and orchestra. 10 students are in the band and choir. 5 students are in the choir and orchestra. 3 students are in the band, choir, and orchestra How many students participated only in the choir