Question

Predict square root of $3136$ using Vilokanam method.

• A. $54$
• B. $56$
• C. $64$
• D. $66$

Answer 1

Answer: (B)

$56$

We have to find the square root of $3136$ using Vilokanam method.

Its unit digit is $6$.

Therefore, the unit digit of the square root will be $4$ or $6$.

Ignoring the last two digits (unit digit and ten’s digit) we get $31$.

The greatest number whose square is less than or equal to $31$ is $5$.

Adjusting above obtained two unit digits $4$ or $6$ to the right of $5$, we get two numbers $54$ and $56$.

The unique number with unit digit $5$ which lies between $54$ and $56$ is $55$.

And $(55{)}^2=3025$

Since, $3136>3025$, therefore, the required square root is $56$.

Thus $\sqrt{3136}=56$