Probability is computed as follows:
[tex]\text{probability}=\frac{\text{ number of favorable outcomes}}{\text{ total number of outcomes}}[/tex]When rolling a pair of six-sided dice, the total number of outcomes is 36 (= 6x6)
(a) number of favorable outcomes: 3 (dice: 1 and 3, 2 and 2, 3 and 1)
Then, the probability that the sum of the numbers on your dice is exactly 4 is:
[tex]\text{probability }=\frac{3}{36}[/tex](b) number of favorable outcomes: 1 (dice: 1 and 1)
Then, the probability that the sum of the numbers on your dice is at most 2 is:
[tex]\text{probability }=\frac{1}{36}[/tex](c) number of favorable outcomes: 1 (dice: 6 and 6)
Then, the probability that the sum of the numbers on your dice is at least 12 is:
[tex]\text{probability }=\frac{1}{36}[/tex]