# Thread: How many functions, onto, and one-to-ones?

1. ## How many functions, onto, and one-to-ones?

Please help. I have been working on the following problem:

How many functions are there from , a set with two elements, to , a set with three elements?

How many of these functions are one-to-one?

How many are onto?

I get 9 functions, 6 one-to-one and 0 onto. Is this right?

2. ## Re: How many functions, onto, and one-to-ones?

Originally Posted by brianjasperman
Please help. I have been working on the following problem:

How many functions are there from , a set with two elements, to , a set with three elements?
How many of these functions are one-to-one?
How many are onto?

I get 9 functions, 6 one-to-one and 0 onto. Is this right?
Each of those answers is correct.