AIEEE 2012 (Offline) 29th April Code AQuestion 1
Let $X=\{1,2,3,4,5\}$. The number of different ordered pairs $(Y,Z)$ that can be formed such that $Y\subseteq X$, $Z\subseteq X$ and $Y\cap Z$ is empty, is :
Permutation and Combination
Solution
Each element lies in $Y$ only, $Z$ only or neither: $3$ choices, so $3^5$ pairs.