How does Scrabble relate to probability?

by multiplying amount of letters in the alphabet by the number of times each letter appears on a scrabble piece. then just there is 10 letter "a" tiles and for example there is 250 tiles in total, that would mean the odds of gettin the letter "a" is 1 in 25. so the amount of times the letter appears divided into the amount of tiles will give you the probability.