Question

Identify the type of set

$B=\{x:xisacompositenumberlessthan5\}$.

• A. Singleton Set
• B. Null Set
• C. Finite Set
• D. Infinite Set

Answer 1

Answer: (A)

Singleton Set

We have to identify the type of set.
Given $B=\left\{x|xisacompositenumberlessthan5\right\}$
We know that, A composite number is a positive integer which is not prime (that is, which has factors other than $1$ and itself).
In a set of numbers less than $5$, the only number which has factors other than itself and $1$ is $4$.

$\therefore B=\left\{4\right\}$ which is a singleton set.
Hence $B$ is a singleton set.