Question

What is the cardinality of the set of odd positive integers less than $10$?

• A. $10$
• B. $5$
• C. $3$
• D. $20$

Answer 1

The correct option is B $5$

Let $S$ be the set of odd positive integer less than $10$

$\therefore S=\{1,3,5,7,9\}$.

Then, Cardinality of set $S=|S|=$ no. of elements in $S$ which is $5$.

Hence, option B is correct.