Q167 / 270 · NDA 2012 (Phase 2) · Mathematics
Let $\mathrm{A}=\{x \in \mathrm{~W}$, the set of whole numbers and $x \lt 3\}$, $\mathrm{B}=\{x \in \mathrm{~N}$, the set of natural numbers and $2 \leq x \lt 4\}$ and $C=\{3,4\}$, then how many elements will $(A \cup B) \times C$ contain?
- A$6$
- Correct answerB$8$
- C$10$
- D$12$
Solution
$\begin{aligned} & A=\{0,1,2\}, B=\{2,3\}, C=\{3,4\} \\ & \therefore A \cup B=\{0,1,2,3\}\end{aligned}$
$\therefore$ no. of elements in $(A \cup B) \times C$ will be 8 .
Hence, the correct answer is option: 'B'.