Front-row tickets for a concert cost $60. After every 5 rows, the ticket price goes down by $5. What is the total amount of money generated by a full house? Info: There are 20 rows that increase by 3 seats each time starting with 18.

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=1 20 18+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)

I think I got it, but just in case ... tell me the whole thing again. I wasn't listening.