Question

Find the square of 101 using an appropriate algebraic identity.

• A. 10201
• B. 10101
• C. 10001
• D. 20102

Answer 1

The correct option is A 10201

${101}^2$ can be written as $(100+1{)}^2.$

Using the identity,
$(a+b{)}^2=a^2+2ab+b^2$
We get, $(100+1{)}^2={100}^2+2\times 100\times 1+1^2$
$=10000+200+1=10201$