SOLUTION: 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? 1170 735 1230

Algebra ->  Trigonometry-basics -> SOLUTION: 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? 1170 735 1230       Log On


   

Question 1135569: 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?
1170

735

1230

600
Answer by ikleyn(52866) About Me  (Show Source):
You can put this solution on YOUR website!
.

They ask you to calculate the sum of the arithmetic progression.

The first term is 10, the number of the terms is 30, the common difference is 2.

Go to the lessons

    - Arithmetic progressions
    - The proofs of the formulas for arithmetic progressions
    - Problems on arithmetic progressions

in this site and learn from there how to calculate the sum of an arithmetic progression.

Then you will be able to do it on your own.

Or see the lesson
    - Word problems on arithmetic progressions, Problem 4,
which is your TEMPLATE.