Thinking Mathematically (6th Edition)

A = {x| x∊N and 3 $\lt$ x $\lt$ 10} B = the set of natural numbers between 2 and 16 Set A represents A = {4,5,6,7,8,9} Set B represents B = {3,4,5,6,7,8,9,10,11,12,13,14,15} If we observe the two sets all the elements of set A are present in set B, but the sets are not equal. Therefore A is proper subset of set B i.e. A ⊂ B.