Permutations question - 4k blocks

Hi Folks,

I'm not a student - but investigating the theoretical side of my work appears to have lead me to mathematics.

So, I have a question and I hope I'm in the right section . I'm happy to receive a straight answer but would also like to learn how the answer was derived so I can do it myself in future.

It's to do with how data is stored on a disk:

Storage is held in the following units (ascending order)

Bits - Bytes - Kilobytes (or k)

Let's say that each block of data held on the disk is 4k in size - that means for arguments sake that there are 4000 bytes per 4k block.

Each byte is made up of 8 bits. The bits are boolean.

Now - I'm advised that there are 256 combinations of 1 and 0 in an 8 bit byte. If there are 4000 of them in a 4k block, how many permutations of 4k block are there?

Any help appreciated.