The three-letter words are of these types VVV, VCV, CVV Case 1: VVV Choose the first vowel any of 5 ways Choose the second vowel any of 5 ways Choose the third vowel any of 5 ways. That's 5*5*5 = 125 ways. Case 2: VCV Choose the first vowel any of 5 ways Choose the consonant any of 7 ways Choose the remaining vowel any of 5 ways. That's 5*7*5 = 175 ways. Case 3: CVV Choose the consonant any of 7 ways Choose the first vowel any of 5 ways Choose the remaining vowel any of 5 ways. That's 5*5*7 = 175 ways. Total = 125 + 175 + 175 = 475 ways. Edwin