Solve the problem.
-A school auditorium 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 auditorium?
A)2448 seats
B)4896 seats
C)2397 seats
D)4794 seats

Question

Quizplus · Accepted Answer

To find the total number of seats, we need to find the sum of the seats in each row. The number of seats in each row follows an arithmetic sequence with the first term being 21 and common difference of 3. We can use the formula for the sum of an arithmetic sequence:

S = (n/2)(2a + (n-1)d)

where S is the sum of the sequence, n is the number of terms, a is the first term, and d is the common difference.

Using this formula, we can find the sum of the seats in the first 34 rows:

S = (34/2)(2(21) + (34-1)(3))
S = 17(42 + 99)
S = 17(141)
S = 2397

Therefore, there are 2397 seats in the auditorium. The correct answer is C.

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