If A = {1, 2, 3}

Formula:-if A and B are two non-empty finite sets containing m and n

(i) Number of function from A to B = n^m

(ii) Number of one–one function from A to B

(iii) Number of one-one and onto function from A to B

(iv) Number of onto function from A to B=

given: -

A = {1, 2, 3} and B = {a, b}

n(A)=3, and n(B)=2

total number of functions=2³=8