2005 CEMC Gauss (Grade 7) Problems/Problem 9
Problem
A movie theatre has eleven rows of seats. The rows are numbered from 
to 
. Odd-numbered rows have 
seats and even-numbered rows have 
seats. How many seats are there in the theatre?
Solution
There are six odd-numbered rows (rows 
).
These rows have 
seats in total.
There are five even-numbered rows (rows 
).
These rows have 
seats in total.
Therefore, there are 
seats in total in the theatre. The answer is 
.
