Answer:
544 words
Step-by-step explanation:
The number of 4 letter words can be constructed from ABCDE would be 5^4 = 625
The number of 4 letter words can be constructed using BCD would be 3^4 = 81
So the number of words that use at least one vowel would be 5^4 - 3^4 = 625-81 = 544