Given that U = {3, 7, 9, 11, 15, 17, 18}, M = {3, 7, 9, 11} and N = {7, 11, 15, 17},

Find

i. M – N

ii. N – M

iii. N’ – M

iv. M’ – N

v. M ∩ (M – N)

vi. N ∪ (N – M)

vii. n(M – N)

U = {3, 7, 9, 11, 15, 17, 18}

M = {3, 7, 9, 11}

N = {7, 11, 15, 17}

i. M – N = {3, 9} [elements that are present in M but not in N]

ii. N – M = {15, 17} [elements that are present in N but not in M]

iii. U = {3, 7, 9, 11, 15, 17, 18}

M = {3, 7, 9, 11}

N = {7, 11, 15, 17}

∴ N’ = {3, 9, 18}

∴ N’ – M = {18} [elements that are present in N’ but not in M]

iv. U = {3, 7, 9, 11, 15, 17, 18}

M = {3, 7, 9, 11}

N = {7, 11, 15, 17}

∴ M’ = {15, 17, 18} [elements that are present in U but not in M]

∴ M’ – N = {18} [elements that are present in M’ but not in N]

v. M = {3, 7, 9, 11}

M – N = {3, 9}

∴ M ∩ (M – N) = {3, 9} [elements that are present in both in M and (M – N)]

vi. N = {7, 11, 15, 17}

N – M = {15, 17}

∴ N ∪ (N – M) = {7, 11, 15, 17} [elements that are present in either N or (N – M)]

vii. M – N = {3, 9}

∴ n(M – N) = 2 [no. of elements in (M – N)]