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Example 9
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Let A = {1, 2} and B = {3, 4}. Find the number of relations from A to B.

Given A = {1,2} & B = {3,4}

Number of relations from A to B = 2Number of elements in A × B

= 2Number of elements in set A × Number of elements in set B

= 2n(A) × n(B)

Number of elements in set A = 2

Number of elements in set B = 2

Number of relations from A to B = 2n(A) × n(B)

= 22 × 2