The maximum sum we can get a pair of six sided dice is 12. So probability to get a sum of 22 is 0.
P(getting a sum of 22) = number of favorable outcome/ total outcome.
Number of favorable outcome = 0 .....as the maximum sum we can get is 12.
Total outcome = 6*6 = 36
P(getting a sum of 22) = 0/36 =0
I hope this helps. If you have any question you can ask me by comments.