if you have 15 stones and you have 5 colums and 3 rows and there's 8gray stones and 7 white stones what is the rule.

There is no rule. Arrange them any way you like.

To determine the rule based on the given information, you need to analyze the distribution of the gray and white stones in the five columns and three rows. Here's how you can calculate it:

1. Start by creating a visual representation of the setup. You have five columns and three rows:

```
Col1 Col2 Col3 Col4 Col5
Row1 ___ ___ ___ ___ ___
Row2 ___ ___ ___ ___ ___
Row3 ___ ___ ___ ___ ___
```

2. Now, fill in the gray stones (represented as "G") and white stones (represented as "W") in their respective positions. According to the information provided, there are 8 gray stones and 7 white stones in total.

For example, if the first column (Col1) has three gray stones and two white stones, it would look like this:

```
Col1 Col2 Col3 Col4 Col5
Row1 G ___ ___ ___ ___
Row2 G ___ ___ ___ ___
Row3 W ___ ___ ___ ___
```

Continue this process until all the stones are placed in their respective positions.

3. After all the stones are placed, observe the pattern or rule that emerges. Look for any consistent pattern between the distribution of gray and white stones across the columns and rows.

For example, you might notice that the number of gray stones is always greater than the number of white stones in each column, or that the number of white stones increases from left to right across the columns.

Analyzing the pattern will help you identify the rule based on the given information about the arrangement of the stones.

Please provide any additional information or clarification if this explanation does not completely answer your question.