Question

A 20-row theater has three sections of seating. In each section,

the number of seats in a row increases by one with each successive row.The
first row of the middle section has 10 seats.The first row of each of the two side
sections has 4 seats.
a. Find the total number of chairs in each section.Then find the total seating
capacity of the theater.
b. Write an arithmetic series to represent each section.

Answer 1

I'm not 100% sure but try A.

Answer 2

The total no. of chairs are 930.
for each of the end sections ∑i=423i