n a 20 row theater, the number of seats increases by 3 with each successive row. The first row has 18 seats.
a. Write an arithmetic series in summation notation to represent the number of seats in the theater,∑n=12018+3(n−1)b. What is the total seating capacity of the theater?
930 seats
c. Front row seats cost $60. After every 5 rows, the price drops $5. What is the amount generated by a full house?
$46950
2. An arithmetic series has a first term of 4. The sum of the first 40 terms is 6080. Find the value of the 40th term?
use the formula
sum of first n terms = n/2 * (s1 + sn)
6080 = 40/2 * (4 + sn)