+1839 How many ways can you write two different letters chosen from
A B C D E F G H I J K L M N O P
so that they are in alphabetical order, and the first letter is a vowel? For example, AF and EN count, but DE and KC do not.
+1215
How many ways can you write two different letters chosen from
A B C D E F G H I J K L M N O P
so that they are in alphabetical order, and the first letter is a vowel?
34 ways
If A is the first letter, then 15 possibilities
If E is the first letter, then 11 possibilities
If I is the first letter, then 7 possibilities
If O is the first letter, then 1 possibility
Add them up.
