Final answer:
The probability that the balls have the same number is 1/165 or approximately 0.00606.
Step-by-step explanation:
To find the probability that the balls have the same number, we need to consider the number of favorable outcomes and the total number of possible outcomes.
- Number of favorable outcomes: Since there are 11 balls and each ball has a unique number, there is only 1 way to choose 3 balls with the same number.
- Total number of possible outcomes: The total number of ways to choose 3 balls from the 11 balls without replacement is given by the combination formula: C(11,3) = 165.
Therefore, the probability is given by:
Probability = Number of favorable outcomes / Total number of possible outcomes = 1 / 165 = 0.00606 (rounded to the nearest millionth).