# math

Cinema 2 has 25 seats in the first row and 30 rows in all. Each successive row contains one additional seat. How many seats are in the theater

1. 👍
2. 👎
3. 👁
1. so you want
25+26+.. for 30 terms
an arithmetic series where a=25 , d=1 ,and n=30
sum(3) = (30/2)(50 + 29(1)) = 1185

1. 👍
2. 👎
2. a1=25 d=1 n=30

sn=30/2{2(25)+(30-1)1}
sn=15(50+29)
sn=15(79)
sn=1,185 seats in the theatre

1. 👍
2. 👎
3. A theater has 30 rows of seats. The first row contains 20 sets, the second row contains 21 seats, and so on, each row has one more seat than the previous one. How many seats are there in the theater?

1. 👍
2. 👎
4. A hall has 35 rows. Each successive row contains two additional seats. If the first row has 20 seats, how many seats are in the hall?

1. 👍
2. 👎

## Similar Questions

1. ### Math (arithmetic)

The total seating capacity of an auditorium is 1,065. The first row has 21 seats arithmetic series and each row has one seat more than the row in front of it. How many rows of seats are there in the auditorium?

2. ### precalculus

The first row of seating in section A of an arena has 7 seats. There are 25 rows in section A, each row containing two more seats than the row preceeding it. How many seats are in section A? How do you use geometric sequence to

3. ### Math

An auditorium has 30 rows with 10 seats in the first row, 12 in the second row, 14 in the third row, and so forth. How many seats are in the auditorium My answer is 1170 but the way I figured out the problem was by listing numbers

4. ### Math

an auditorium has 50 rows of seats. THe first row has 20 seats, the row has 21 seats, the third row has 22 seats, and so on. each row having one more seat than the previous row. How many seats are there all together?

Write a real-world situation that could be modeled by the equation 24/y=3. Then solve the problem. My answer: There are 24 seats available at the movies. There were total of 3 rows after the seats were divided and more seats on

2. ### Math

An auditorium has 50 rows of seats. The first row has 20 seats, the second row has 21, the third row has 22 seats, and so on, each row having one more seat than the previous row. How many seats are there all together? a. write 2

3. ### Math

The first row of a school concert hall has 25 seats and each row after the first has one more seat than the row before it there are 32 rows of seats write the rule or equation for the number of seats in the nth row 35 students

4. ### Math

The first row of a concert hall has 25 seats and each row after the first has one more seat than the row before it. There are 2 rows of seat. 1)Write a rule for the number of seats in the nth row. 2)35 students from a class want

1. ### Math

A small aeroplane has 14 seats for passengers. The seats are arranged in 4 rows of 3 seats and a back row of 2 seats . 12 passengers board the aeroplane. (i) How many possible seating arrangements are there for the 12 passengers?

2. ### math help!

a hockey arena has a total seating capacity of 15690.the first row of seats around the rink has 262 seats. the number of seats in each subsequent row increases by 18. how many rows of seats are in the arena?

3. ### MAth

The front row of a stadium has 25 seats. Each of the other rows has two more seats than the row in front of it. how many seats are there altogether in the first 20 rows? i know how to do this in the "long" way but how do you do

4. ### Algebra

A rectangular auditorium seats 1960 people. The number of seats in each row exceeds the number of rows by 9. Find the number of seats in each row. Thanks!