[jacks]

If \( A=\{a_{1},a_{2},a_{3},.............,a_{m}\} \) and \( B=\{b_{1},b_{2},b_{3},.............,b_{n}\} \). Then number of Surjective function from \( A\rightarrow B \) in different cases

\( (a) \) If \( m>n \)

\( (b) \) If \( m=n \)

\( (c) \) If \( m<n \)

[Phicar]

Hi

Is a combinatorial problem..What have you done?

for example....(a) if m>n you have more elements in A than the ones you have in B...So you must think about in how many group of couples(with surjective funcion(all the elements in B have a couple in A and you can not map a element in a to two or more elements in B) conditions) you are able form.

If you still have problems let us know.

cheers..