There are 36 possible combinations that can occur when 2 dice are rolled. For the sake of this question, we'll count instances where dice 1 = 3/dice 2 = 2 and dice 1 = 2/dice 2 = 3.
Now, let's think about all of the possible ways a total of 5 could be rolled.
1 + 4
2 + 3
3 + 2
4 + 1
That's 4 possibilities to roll a total of 5 out of 36 possible outcomes.
4 / 36 = ? / 180
---Now, we need to use a proportion in order to figure out the possibilities out of 180.
36x = 720
x = 20
If you rolled a pair of fair dice 180 times, you would expect to roll a total of 5, 20 times.
Hope this helps!