How many 4-letter words with at least one vowel can be constructed from the letters A,B, C, D , E, and F ? (Note that B, C, D, and F are consonants, any word is valid, not just English language words, and letters may be used more than once.)
We can do this one by exclusion
Possible 4-letter "words" = (6)^4
Possible "words" containing only the consonants listed = (4)^4
So.....possible "words" with at least one vowel = ( 6)^4 - (4)^4 = 1296 - 256 = 1040
