Question

If A = {1, 2, 3, 4}; B = {1, 2, 3, 5, 6} then find A ∩ B and B ∩ A. Are they equal ?

Answer 1

Given sets are A = {1, 2, 3, 4} and B = {1,2,3, 5,6} 

A ∩ B = {1,2, 3,4} ∩ {1,2, 3, 5, 6} 

= {1,2,3} …… (1) 

B ∩ A = {1, 2, 3, 5, 6} ∩ {1, 2, 3, 4} 

= {1,2,3} …….(2) 

From (1) and (2) 

A ∩ B and B ∩ A are same.