Homework Help: math

Posted by mary on Sunday, April 18, 2010 at 3:24pm.

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?

math - Reiny, Sunday, April 18, 2010 at 3:37pm
looks like an arithmetic series where
a = 10, d=2 and n=30

sum(30) = (30/2)[2(10) + (29)(2)]
= 15[20+58] = 1170

(using the standard formula for the sum of n terms)

Answer this Question

Related Questions

Math - An auditorium has 30 rows with 10 seats in the first row, 12 in the ...
math - Determine the seating capacity of an auditorium with 10 rows of seats if ...
math - An auditorium has 49 rows of seats. The first row contains 40 seats. As ...
Math - an auditorium has 50 rows of seats. THe first row has 20 seats, the row ...
Math - An auditorium has 50 rows of seats. The first row has 20 seats, the ...
arithmetic - An auditorium has 20 rows of seats.These are 20 seats in the first ...
math- Algebra 2 - An auditorium has 49 rows of seats. The first row contains 40 ...
math (plz help) - In a movie theater, theater A has 30 seats in the first row. ...
math - In a movie theater, Theater A has 30 seats in the first row. Each next ...
math - find the number of seat in a theater containing 30 rows if the first row ...

For Further Reading

First Name:
School Subject:
Answer: