Question

Which of the following is a singleton set?

• A. $\{x:|x|<1,x\in Z\}$
• B. $\{x:|x|=5,x\in Z\}$
• C. $\left\{x:x^2=1,x\in Z\right\}$
• D. $\left\{x:x^2+x+1=0,x\in R\right\}$

Answer 1

Answer: (A)

$|x|<1\Rightarrow -1<x<1$
$(x=0$ integer satisfies $it)$