Answer = J= 144
Step by step:
24x6 = 144
The answer is 2,320 seats in the amphitheater. Since the seats are increasing at a rate of 4 more seats each row, then just add 4 to the number for each past row starting at 32 since that's where the rest is unknown. Once you find all he numbers just add them up to get your answer.
I hope I helped!