Please help!

1.) Three-letter 'words' are to be made by arranging the letters of the word METHODS. What is the probability that the word begins with a vowel?

I tried to do this question by finding the total number of possibilities then using the formula Pr(event) = Relevant/Total. I did not know how to successfully represent 1 vowel and i did it like this: 7p1 or n English, 1 letter picked out of 7, is this correct?2.) There are 5 vowels and 21 consonants in the English alphabet. How many different four-letter words can be formed that contain two different vowels and two different consonants?

For this question i attempted to use permutative formula and got the following: 5p2 x 21p2 and found that it was 8400 ways, it was ultimately incorrect, could someone please explain?

Thanks!