Question

How many 3 letter permutations can be made from the letters COMPUTER?

Answer 1

`336`

Explanation:

Assuming letters can not be reused:

There are `8` choices for the first letter,
and for each of these:
`color(white)("XXX")`there are `7` choices for the second letter,
`color(white)("XXX")`and for each of these
`color(white)("XXXXXX")`there are `6` choices for the third letter.

Therefore there are `8xx7xx6=336` choice results (permutations).