SOLUTION: I really need help solving the following problem. An outdoor amphitheater has 29 seats in the first row, 31 in the second row, 33 in the third row, and so on. There are 36 rows alt

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: I really need help solving the following problem. An outdoor amphitheater has 29 seats in the first row, 31 in the second row, 33 in the third row, and so on. There are 36 rows alt      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 766248: I really need help solving the following problem. An outdoor amphitheater has 29 seats in the first row, 31 in the second row, 33 in the third row, and so on. There are 36 rows altogether. How many can the amphitheater seat?
Found 2 solutions by stanbon, MathTherapy:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
I really need help solving the following problem. An outdoor amphitheater has 29 seats in the first row, 31 in the second row, 33 in the third row, and so on. There are 36 rows altogether. How many can the amphitheater seat?
a(36) = 29+(35)*2 = 99
-----
S(33) = (33/2)(2+99)
s(33) = 33*50 = 1650 (amphetheater capacity)
===============
Cheers,
Stan H.
================

Answer by MathTherapy(10557) About Me  (Show Source):
You can put this solution on YOUR website!
I really need help solving the following problem. An outdoor amphitheater has 29 seats in the first row, 31 in the second row, 33 in the third row, and so on. There are 36 rows altogether. How many can the amphitheater seat?

The last row (36th row) has 99 seats

Formula for the sum of an arithmetic series: S%5Bn%5D+=+%28n%2F2%29%28a%5B1%5D+%2B+a%5Bn%5D%29, where:

S%5Bn%5D is the sum of the terms, or sum of rows, which is sum of 36 rows

n = number of terms (rows) in the series, which is 36

a%5B1%5D = 1st term, or amount in 1st row, which is 29

a%5Bn%5D = nth term, or in this case, the 36th, or last term, which has 99 seats

S%5Bn%5D+=+%28n%2F2%29%28a%5B1%5D+%2B+a%5Bn%5D%29 then becomes: S%5B36%5D+=+%2836%2F2%29%2829+%2B+99%29 ----- highlight_green%282304%29 seat-capacity

You can do a manual check, or use excel to do it!!!