MCQ
If A and B are two disjoint sets, then $\text{n(A}\cup\text{B)}$ is equal to:
  • A
    $\text{n(A) + n(B)}$
  • B
    $\text{n(A) + n(B)} - \text{n(A}\cap\text{B)}$
  • C
    $\text{n(A) + n(B) + n(A}\cap\text{B)}$
  • D
    $\text{n(A) n(B)}.$

Answer

  1. $\text{n(A) + n(B)}.$

Solution:

Two sets are disjoint if they do not  have a common element in them, i.e., $\text{A}\cap\text{B}=\phi.$

$\therefore\text{n(A}\cup\text{B) = n(A) + n(B)}.$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free