SOLUTION: A theater has 37 seats in the first row, 41 seats in the second row, 45 seats in the third row and so on. how many seats are in row 15

Algebra ->  Sequences-and-series -> SOLUTION: A theater has 37 seats in the first row, 41 seats in the second row, 45 seats in the third row and so on. how many seats are in row 15      Log On


   

Question 726661: A theater has 37 seats in the first row, 41 seats in the second row, 45 seats in the third row and so on. how many seats are in row 15
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
This is an arithmetic sequence since the common difference is d = 41 - 37 = 4 each time.

First term: a1 = 37

Common Difference: d = 4

a(n) = a1 + d(n-1)

a(n) = 37 + 4(n-1)

a(n) = 37 + 4n-4

a(n) = 4n + 33

a(15) = 4(15) + 33

a(15) = 60 + 33

a(15) = 93

There are 93 seats in row 15.