Answer :
Well, since this is expected, and not experimental, each side has a fair chance of being rolled, which is 1/6 of the time, which is 4/24 rolls. So since we have 2 numbers to expect, we do 4+4 = 8, and 8/24 = 1/3. So, getting a 2 or 5, we have a 1/3 chance, which was 8/24 before we simplified it. Hope this helped!