A number cube with sides labeled 1-6 is rolled two times, and the sum of the numbers that end face up is calculated. What is the probability that the sum of the numbers is 3 ? A. \( \frac{1}{18} \) B. \( \frac{1}{12} \) C. \( \frac{1}{9} \) D. \( \frac{1}{2} \)

Step 1 ：Determine the total number of possible outcomes by multiplying the number of sides on the number cube by itself: 6 * 6.

Step 2 ：Find the number of outcomes resulting in a sum of 3: (1, 2) and (2, 1). There are 2 favorable outcomes.

Step 3 ：Calculate the probability by dividing the number of favorable outcomes by the total number of outcomes: \( \frac{2}{36} \)