Answers
15. 2/9 (two ninths)
16. 5/9 (five ninths)
17. 1/3 (one third)
18. 9/9 (nine ninths)
19. 0
20. 7/9 (seven ninths)
Explanations
There are nine letters.
There is one T.
There are 4 E's.
There are two N's.
There are two S's.
15. You know that there are two S's. Two S's out of nine total letters is 2/9. The probability that an S is selected is 2/9.
16. A consonant is a letter that is not a vowel. The consonants in TENNESSEE are T, N, and S. There is one T, two N's, and two S's, meaning there are 5 consonants. Five consonants out of nine total letters is 5/9. The probability that a consonant is selected is 5/9.
17. You know that there is one T and two N's. This is a total of three letters. The probability of getting on of these three letters is 3/9. 3/9 simplified is 1/3. The probability of selecting a T or N is 1/3.
18. You know that there are no V's in TENNESSEE. Therefore, no matter what letter you select, there is a 100% chance you'll get a number that is not V. All nine letters are not the letter V, so the probability of selecting a letter that is not V is 1/1 or 1.
19. You know that there are no W's in TENNESSEE either. Therefore, whichever letter you select, you will not get a W. The chance of selecting a W is 0/9 or 0.
20. There are four S's. That means there are five letters that are not S. These are: T, N, N, S, S. Five letters out of nine letters in total is 5/9. The probability of selecting a number that is not S is 5/9.