Answer:
1170
Explanation:
start with 10 and add 2 to each row. Then add each number up when you have 30 numbers.
10,12,14,16,18,20,22,24,26,28,30,32,34,36,38,40,42,44, 46,48,
50,52,54,56,58,60,62,64,66,68.
You get 1170 seats total.
I know there is a type of equation that can be used but I wanted to be 1000 percent sure of my answer to you to be correct.