What's the probability a number is odd given that it's an integer between 0 and 11?

A odd number lie between 0 and 11 (0 and 11 not included), it means that total of ten numbers, starting from {1,2,3 ...,10} form our sample space.

sample space=s={1,2,3 ...,10}=total 10 numbers

So,

m=total no. of odd numbers{1,3,5,7,9} in our sample space=5 numbers

probability that number is odd=p=m/s

p=5/10=0.5