Solve the problem.
-A theater has 34 rows with 21 seats in the first row, 24 in the second row, 27 in the third row, and so forth. How many seats are in the theater?
A) 2448 seats
B) 4896 seats
C) 2397 seats
D) 4794 seats

Question

Quizplus · Accepted Answer

This is an arithmetic sequence with the first term $a_1 = 21$, common difference $d = 3$, and number of terms $n = 34$. The total number of seats is found using the formula for the sum of an arithmetic series: $S_n = \frac{n}{2}[2a_1 + (n-1)d]$. Substituting the given values: $S_{34} = \frac{34}{2}[2(21) + (34-1)3] = 17[42 + 99] = 17 \times 141 = 2397$ seats.

Solve the Problem. -A Theater Has 34 Rows with 21 Seats in the Seats