SOLUTION: a 40 row theater has 10 seats in the front row. the second row has 11 seats. if each row has one more than the row in front of it how many seats are there in the theater

Algebra ->  Permutations -> SOLUTION: a 40 row theater has 10 seats in the front row. the second row has 11 seats. if each row has one more than the row in front of it how many seats are there in the theater      Log On


   



Question 607052: a 40 row theater has 10 seats in the front row. the second row has 11 seats. if each row has one more than the row in front of it how many seats are there in the theater
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
The rows are:
+10+%2B+0+
+10+%2B+1+
+10+%2B+2+
+10+%2B+3+
All the way to +40+ rows, so
This is the same as:
+10%2A40+ + 0 + 1 + 2 + 3 + ... + 39
This is +400+ + (1/2) x (total number of rows) x 39
+400+%2B+%281%2F2%29%2A40%2A39+
+400+%2B+780+=+1180+
There are 1180 seats