There are five vowels. Notice that any of the vowels could be chosen from 0 though 5 times in any given combination. We therefore need the number of combinations of 5 from 5 _with replacement_.
This is the number ( 5 + 5 - 1 ) choose 5 = 126.
There are 3 consonants from 21 and 2 vowels from 5. That gives 21C3 * 5C2 combinations = 21*20*19/(3*2*1) *5*4/(2*1) = 1330*10 = 13300 combinations in all.
Two make combinations you would take 2x1=2 combinations only
27^27
6
720
There are 3 consonants from 21 and 2 vowels from 5. That gives 21C3 * 5C2 combinations = 21*20*19/(3*2*1) *5*4/(2*1) = 1330*10 = 13300 combinations in all.
That is a trick question. You can't make a four letter word using all five vowels.
The other combinations you can make using that letter combination are:lightlightssighsight
The word "your" has one vowel, which is the letter 'o'.
1
5 x 21 = 105
3,124,550 possible combinations
21^4
Two make combinations you would take 2x1=2 combinations only
27^27
There are many five letter words with no vowels. Crypt, Cysts, Dryly, Flyby, Glyph and Gypsy are some examples. If you don't consider Y a vowel!
You did not give us the set to work with...