question_answer 1)

                There are 500 children in a school.  For a P. T. drill they have to stand in such a manner that the number of rows is equal to number of columns. How many children would be left out in this arrangement?             

Answer:

                Let the number of rows be \[x\]. Then the number of columns is \[x\]. So, the number of children is \[x\times x={{x}^{2}}\] which is a perfect square. Let us find out the square root of 500 by division method.                             

	22
2	\[\overline{5}\] \[\overline{00}\] ?4
42	100 ?84
	16

We get the remainder 16. It shows that \[{{22}^{2}}\] is less than 500 by 16. This means that 16 children would be left out in this arrangement.