Question

How many consonants are in the word vowel?

Answer 1

All vowel are 5 and consonant are 3

Answer 2

B.3 
your vowels will be A, E, I, O, U
your consonants are everything else
In the word vowel, you have 1 o, 1 e, and so you subtract 2 from 5, which gives you a total of 3 letters left. These 3 letters are consonants.
 
Hope this helps