A new movie theater has stadium seating. The first row has 10 seats. Each additional row has 4 seats more than the row before it. How many seats are in the theater if there are 16 rows of seats?

Question

anonymous · Answer

A new movie theater has stadium seating. The first row has 10 seats. Each additional row has 4 seats more than the row before it. How many seats are in the theater if there are 16 rows of seats?

anonymous · Answer

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I'm sure there's a shorter way to do this, but this is what I did and how I got the answer.

There are 640 seats.