Question

Let A = {a, b, c, d} and B = {1, 2, 3, 4}.
a) How many functions f: A -> B are there?

b) How many functions f: A -> B satisfy f(a) = 2?

Answer 1

Does that mean A onto B?

Answer 2

Is is a bold arrow in the problem\[A rightarrowB \]

Answer 3

\(A \rightarrow B\) you mean?

Answer 4

Yes that is it

Answer 5

Hmm.. I'm not quite sure about this particular problem.

Answer 6

know anyone who might.

Answer 7

@ParthKohli can you help, please? c:

Answer 8

Hint: if \(A\) has \(a\) elements and \(B\) has \(b\) elements then there are \(b^a\) functions from \(A \to B\).

Answer 9

Okay

Answer 10

still a little lost

Answer 11

How many elements does \(A\) have in this question?

Answer 12

Hey, do you want the number of onto functions?

Answer 13

4

Answer 14

how about onto and 1-1 then its n!