Total possible outcomes are= 6×6=36
For example, if you roll a 1 on the blue dice, you cannot roll another 1 (since 1 is not bigger than 1).
Rolling a 2, you'd have 4 possible choices left (you cannot roll a 1 or 2 since they are less than 2).
(1/6)<-- picking a 1/2/3/4/5/6 out of everything;
(1/6)(5/6)=5/36 <-- (5/6) possibilities of picking a number bigger than 1
(1/6)(4/6)=4/36 <-- (4/6) possibilities of picking a number bigger than 2
(1/6)(3/6)=3/36
(1/6)(2/6)=2/36
(1/6)(1/6)=1/36
(1/6)(0)=0 <-- Impossible to get a number bigger than 6 in a normal dice
Add all of them together;
(5+4+3+2+1+0)/36=15/36
Therefore, there are 15/36 possibilities of the red die showing a number larger than that of the blue die.
Hope I helped :)
