Question

What could be the possible one's digits of the square root of the following numbers?
$9801$
$99856$
$99800$
$657666025$

• A. $1or9;4or6;0;5$
• B. $2or8;4or6;0;5$
• C. $1or9;2or8;0;5$
• D. $1or9;4or6;5;0$

Answer 1

The correct option is A $1or9;4or6;0;5$

Possible one's digits $=1(\because 1\times 1=1)$
Possible one's digits $=6(\because 6\times 6=36)$
Possible one's digit $=0(\because 0\times 0=0)$
Possible one's digit $=5(\because 5\times 5=25)$