Sets and Functions


  1. In a class, 50 students play cricket, 20 students play football and 10 play both cricket and football. How many play at least one of these two games?









  1. View Hint View Answer Discuss in Forum

    Given: n(C) = 50, n(F) = 20, n(C ∪ F) = 10.

    Correct Option: A

    Given: n(C) = 50, n(F) = 20, n(C ∪ F) = 10.
    Number of students playing at least one of these two games = n (C ∪ F) = n (C) + n (F) – n (C ∩ F)
    = 50 + 20 – 10 = 60.


  1. Which of the following pairs of sets are comparable?









  1. View Hint View Answer Discuss in Forum

    (a) 1∈ A but 1∉ B and 6 ∈ B but 6 ∉ A.

    (b) A = {x: x ∈ N and x ≤ 10} = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10} B = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11}

    (c) {4, 5} ∈ A but {4, 5} ∉ B and 4 ∈ B but 4 ∉ A.

    Correct Option: B

    (a) 1∈ A but 1∉ B and 6 ∈ B but 6 ∉ A.
    ∴ A and B are not comparable.
    (b) A = {x: x ∈ N and x ≤ 10} = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10} B = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11}
    Clearly, A ⊂ B ⇒ A and B are comparable.
    (c) {4, 5} ∈ A but {4, 5} ∉ B and 4 ∈ B but 4 ∉ A.
    ∴ A and B are not comparable.



  1. Write down the power set of A = {8, 9}.









  1. View Hint View Answer Discuss in Forum

    NA

    Correct Option: A

    NA