Q. Let $S = \{ 1,\ 2,\ 3,\ 4\}$. The total number of unordered pairs of disjoint subsets of $S$ is equal to
A) 25
B) 34
C) 42
D) 41
Explanation
(d)
Required number
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ = \frac{3^{4} + 1}{2} = 41$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.