Chapter 13 - Probability - 13-1 Experimental and Theoretical Probability - Practice and Problem-Solving Exercises - Page 827: 9

$\frac{1}{11}$

To calculate probability, we need to divide the number of chances for a certain outcome to occur by the total number of outcomes. In this case, there is one tile with the letter "M" and $11$ in total. When we divide $1$ by $11$, we get $\frac{1}{11}$.