In the set of the first n integers, the number of a square number is approximately sqrt(n). So the probability of a square number is sqrt(n)/n = 1/sqrt(n). As n becomes larger this probability tends towards 0.
There are 11 numbers from 10 to 20 if we include 10 and 20. Of those, only 16 is a perfect square. So the probability if 1/11 or .09 repeating.
You can find probability form a Punnett square by turning fractions into percents
The highest number on probability is 1 or 100%.
If your chi square test has a probability of 0.05 or less it is likely, but not certain, that your hypothesis is not correct.
There could be many questions: What is the probability of rolling an even number. What is the probability of rolling an odd number. What is the probability of rolling a number less than 4. What is the probability of rolling a number more than 3. What is the probability of rolling 1,4, or 6. Basically it could be any question about the probability of rolling half of the faces.