Question

What is the probability of rolling the sum of 5 or 8 on a pair of number cubes?

Answer 1

$|\Omega|=6^2=36\\|A|=\underbrace{4}_{\text{the sum is 5}}+\underbrace{5}_{\text{the sum is 8}}=9\\\\P(A)=\dfrac{9}{36}=\dfrac{1}{4}=25\%$

Answer 2

The probability of rolling a 5 is 4/36 (reduced to 1/9) and the probability of rolling an eight is 5/36. Rolling either would be 9/36 (reduced to 1/4)