Question

If ξ = { 2, 3, 4, 5, 6, 7, 8, 9, 10, 11} 

A = { 3, 5, 7, 9, 11} 

B = {7, 8, 9, 10, 11} then find ( A –B)′ .

Answer 1

A – B = { 3, 5} 

(A – B)′ = { 2, 4, 6, 7, 8, 9, 10, 11}