In a snakes-and-ladders game Kabir throws two dice together. What is the probability that the difference between the two numbers he gets is 3 or more?

There are 36 ordered outcomes. A difference of 3 gives (1,4),(4,1),(2,5),(5,2),(3,6),(6,3) = 6; a difference of 4 gives (1,5),(5,1),(2,6),(6,2) = 4; a difference of 5 gives (1,6),(6,1) = 2. Total = 12, so $P=\frac{12}{36}=\frac{1}{3}.\frac{1}{6}$ counts each pair once instead of in both orders; $\frac{5}{18}$ drops the difference-of-5 pairs; $\frac{2}{3}$ is the complement.