How many words, with or without meaning, can be formed using all the letters of the word EQUATION, using each letter exactly once?

Explanation

There are total 8 letters in the word 'EQUATION'. No. of words formed using all 8 different letters
`= .^(8)P_(8) = (8!)/(0!)`
`= (8 xx 7 xx 6 xx 5 xx 4 xx 3 xx 2xx 1)/(1) = 40320`.