2. A month ago, the guidance office conducted a survey among grade 9 students to determine what elective subject they will take for the next school year. Out of 100 students, 28 said that they will take Foreign Language, 31 said Arts, 42 said Public Relations, 9 said Foreign Language and Arts, 10 said Foreign Language and Public Relation, 6 said Arts and Public Relations, and no student will take all three elective subjects simultaneously for the next school year.
a. How many students will take none of the three elective subjects?
b. How many students will take Foreign Language only?.