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.

Explanation

To solve the problem of how many children would be left out when arranging 500 children in a square formation (where the number of rows equals the number of columns), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the problem**: We need to arrange 500 children in a square formation, meaning the number of rows (r) must equal the number of columns (c). Therefore, the total number of children in such an arrangement would be \( r \times c = r^2 \).

2. **Find the largest perfect square less than or equal to 500**: Since 500 is not a perfect square, we need to find the largest integer \( r \) such that \( r^2 \leq 500 \).

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