Answer:
14 chairs
Explanation:
Let the given length of 1 row is x chairs
3 rows of a given length with 5 chairs left over -> 3x+5 = total number of chairs.
8 rows of that same length if she gets 10 more chairs -> 8x-10 = total number of chairs.
Hence,
3x+5=8x-10 = total number of chairs.
5=5x-10
15=5x
x=3
Hence total number of chairs = 3*3+5 = 14 chairs