A stadium has 10 seats in the first row, 13 in the second, 16 in the third, and the pattern continues for all 56 rows. What is the total seating capacity?

1. The row sizes form an arithmetic sequence with first term 10 seats and common difference 3 seats. 2. Find the size of the last row: a_56 = 10 + (56 - 1)(3). 3. a_56 = 10 + 165 = 175 seats in row 56. 4. The capacity is the arithmetic series S_56 = 56(a_1 + a_56)/2. 5. S_56 = 56(10 + 175)/2 = 28 x 185. 6. 28 x 185 = 5,180 seats in total. 7. Option A multiplies 56 rows by a mid-guess instead of averaging the first and last rows. 8. Option B is 56 x 87.5, an average that drops the first-row seats, and option D miscounts the last row as 177 seats. _Source: OpenStax Algebra and Trigonometry (CC BY 4.0), Ch 13 "Sequences, Probability and Counting Theory", section 13.4 SERIES AND THEIR NOTATIONS_