Solve the problem.
-A local civic theater has 22 seats in the first row and 21 rows in all. Each successive row contains 3 additional seats. How many seats are in the civic theater?
A) 1010 seats
B) 790 seats
C) 1070 seats
D) 1092 seats

Question

Quizplus · Accepted Answer

This is an arithmetic series problem where the first term (a) is 22, the number of terms (n) is 21, and the common difference (d) is 3. The formula for the sum of an arithmetic series is S = n/2[2a + (n-1)d]. Plugging in the values gives S = 21/2[2(22) + (21-1)3] = 21/2[44 + 60] = 21/2[104] = 1092.

Solve the Problem. -A Local Civic Theater Has 22 Seats in the First