The first row of seating in section A of an arena has 7 seats. There are 25 rows in section A, each row containing two more seats than the row preceeding it. How many seats are in section A?

How do you use geometric sequence to solve it?

1 answer

the sequence is not geometric, but arithmetic.
a=7
d=2
S25 = 25/2 (2*7+24*2)