Two dice, one blue and one grey, are thrown together. Referring to the outcome table in Fig. 14.3, what is the probability that the sum of the two numbers is 8? 

There are $6\times 6=36$ equally likely ordered outcomes because the blue die and grey die are distinguishable. A sum of 8 occurs in exactly 5 ordered pairs: $(2,6)$, $(3,5)$, $(4,4)$, $(5,3)$ and $(6,2)$. Therefore the probability is $\frac{5}{36}$.