Answer:
There are 4 chairs in one row.
Step-by-step explanation:
Let be the number of chairs in one row.
That is the length of one row.
Now, from the given data, three rows of length 3x can be formed with one chair left.
Or, if 15 extra chairs given, we can form 7 rows of the same length.
This means that there are chairs in the first case. And since with 15 extra chairs we can form 7 rows, the equation would be
Solving this for '', we get:
Therefore, the length of each row is four.
That is, there are four chairs in one row.