m,t,h,c,s are all consonants. "Mathematics" has 11 letters and 7 of them are consonants and the other 4 are vowels. 100%/11 = 9.091. 9.091 x 4 = 36.36. So, there is a 36.36 % (4/11) chance that you will pick a vowel and a 63.64 % (7/11) chance that you will pick a consonant.
I hope that helps!!!