Question

In a hall, 576 chairs are arranged in rows and columns with the number of rows equal to the number of columns. The chairs from one row and one column are removed. How many chairs are removed?

• A. 49
• B. 47
• C. 57
• D. 59

Answer 1

The correct option is B 47

Initially, the number of chairs is 576.

Since the number of rows is equal to the number of columns, let say ‘a’

$a^2=576$
$a=\sqrt{576}$
$a=\sqrt{2^6\times 3^2}$
$a=2^3\times 3$
a = 24

Now, one row and one column is removed.
Hence, the new number of rows and number of columns is equal to
24 - 1 = 23
New number of chairs = ${23}^2=529$
Therefore, the numbers of chairs removed = 576 - 529 = 47