Set Theory Model Questions Set 2 Practice Questions Answers Test with Solutions & More Shortcuts

Answer: (a)

Total number of boys in the class

n(A ∪ B) = 60

Number of boy play chess n(A) = 45

Number of boy play carrom n(B) = 30

∴ Number of boy play both chess and Carrom

n(A ∩ B) = n(A) + n(B) – n(A ∪ B) = 45 + 30 – 60 = 15

Number of boys plays only carrom n(B) – n(A ∩ B)

= 30 – 15 = 15

42.