Concept:Use the set theory formula for two overlapping sets and the given number of students who offer neither subject.Explanation:Let x be the number of students who offer both French and Arabic.Students who offer only French =80−x.Students who offer only Arabic =60−x.Students who offer neither =20.Total students =150.So, (80−x)+x+(60−x)+20=150.Simplify: 160−x=150.x=160−150=10.Therefore, 10 students offer both subjects.Answer:B. 10