C={f:A→B|2∈f(A) and f is not one-one} Case-I : If f(x)=2∀x∈A then number of function = 1 Case-II : If f(x) = 2 for exactly two elements then total number of many-one function =3C23C1=9 Case-III : If f(x) = 2 for exactly one element then total number of many-one functions =3C13C1=9 Total = 19