Question

Suppose that A = {1,3,5}, B = {1,5}, C = {3,7}, and D = {1,3}. Determine which of these sets are subsets of which other of these sets.

Answer 1

Given $A = \{1,3,5\}, B = \{1,5\}, C = \{3,7\}, \text{and~} D = \{1,3\}.$

Since all the elements in B are also in A and $3 \notin B$ we get, B subset of A.

All the elements in D are also in A and $5 \notin D$ we get, D subset of A.

Since $7\notin A$, C cannot be a subset of A.

Since $3 \notin B$ and $5 \notin D$ neither B subset of D nor D subset of B.