Question

The least number of four digits which is a perfect square is

• A. $1100$
• B. $1210$
• C. $1024$
• D. $1081$

Answer 1

Answer: (C)

$1024$

${31}^2=961{32}^2=1024{33}^3=1089{34}^2=1156$

Least number of four digits = 1000.

(32)2 is more than 1000 by 24.

So, the least number to be added to 1000 is 24.

1000 + 24 = 1024

Therefore, the smallest four digit number which is a perfect square is 1024.