Question

Soldiers are standing in an assembly line in such a way that number of rows is equal to number of columns. If total number of student is 144. The number of rows and columns are:

• A. 9
• B. 12
• C. 15
• D. 18

Answer 1

The correct option is B

12

Since the number of rows is equal to the number of columns, they are making a square.

Let side of the square be ${}^{\prime }{a}^{\prime }$

Total number of student $=a\times a=a^2$

Hence $a^2=144$

$a=\sqrt{144}$

$a=\sqrt{2\times 2\times 2\times 2\times 3\times 3}$

$a=2^4\times 3^2$

$a=2^2\times 3$

$a=12\text{cm}$

So, they are making 12 rows and 12 columns.