Question

An amphitheater has 15 seats in the first​ row, 19 in the​ second, 23 in the​ third, and so​ on, for 29 rows. How many seats are in the​ amphitheater?

Answer 1

There are 2,025 seats in the amphitheater. Keep adding four until you have 29 rows and then add the number of seats in each row to get 2,025!
Hope this answered your question :)

Answer 2

s(33) = 33*50 = 1650 (amphetheater capacity)