If the set A contains 7 elements and the set B contains 10 elements, then the number of one-one functions from A to B is

Explanation

Here, `f:A->B` and set `A` contains `7` elements and set `B` contains `10` elements.

For `f` to be a one-one function each element of `A` should be mapped to a single element of `B`.

So, we have to select `7` element from `10` elements of set `B`.

Now, these `7` elements can themselves be arranged in `7!` ways.

So, required number of one-one functions possible `= C(10,7)*7!.`