Question

Which of the following will have 1 in its unit's place?

• A. ${82}^2$
• B. ${161}^2$
• C. ${77}^2$
• D. ${123}^2$

Answer 1

The correct option is B

${161}^2$

$\text{The square of a number will end in 1,}$$\text{if the digit in the units place is either}$$\text{1 or 9}.$
$\text{We know that}{1}^2=1\text{and}{9}^2=81.$

$\text{Among the given options, 161 has 1}\text{in its units place.}$

$\text{Hence,}(161{)}^2\text{will have 1 in its units}\text{place.}$