nomor 1

A = {x < 8, x ∈ bilangan asli}

   = {1, 2, 3, 4, 5, 6, 7}

B = {x| x < 12, x ∈ bilangan prima}

  = {2, 3, 5, 7, 11}

a. A ∪ B = {1, 2, 3, 4, 5, 6, 7, 11}

b. A ∩ B = {2, 3, 5, 7}

c. = {1, 4, 6}

d. = {11}

nomor 2

A = {1, 2, 3, 4}

B = {bilangan prima kurang dari 6}

  = {2, 3, 5}

C = {x| 2 ≤ x ≤ 7, x ∈ bilangan asli}

   = {2, 3, 4, 5, 6, 7}

(A ∪ B) ∩ C = {1, 2, 3, 4, 5} ∩ {2, 3, 4, 5, 6, 7}

                   = {2, 3, 4, 5}

nomor 3

S = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}

A = {3, 4, 5}

B = {4, 5, 6, 7, 8}

C = {7, 8, 9}

( ∪ B) ∩ C = {1, 2, 4, 5, 6, 7, 8, 9, 10} ∩ {7, 8, 9}

                    = {7, 8, 9}

nomor 4

P = {x| x ≤ 8, x ∈ bilangan asli}

  = {1, 2, 3, 4, 5, 6, 7, 8}

Q = {x| x ≤ 5, x ∈ bilangan cacah}

   = {0, 1, 2, 3, 4, 5}

P - Q = {6, 7, 8}