The letter tiles are W, I, S, D, O, M. Among these, the vowels are I and O.
To find the probability that Abby picks a vowel, we need to determine:
- The total number of letter tiles.
- The number of vowels among those tiles.
There are 6 tiles in total: W, I, S, D, O, M.
There are 2 vowels: I and O.
The probability \( P \) of picking a vowel is given by the formula:
\[ P(\text{vowel}) = \frac{\text{Number of vowels}}{\text{Total number of tiles}} = \frac{2}{6} \]
Now, we simplify the fraction:
\[ \frac{2}{6} = \frac{1}{3} \]
Thus, the probability that Abby picks a vowel is \( \frac{1}{3} \).