Question

In a concert hall, there are 18 chairs

in the first row, and each row has
2 more chairs than the previous
row. There are 15 rows altogether.
How many chairs are there in the
concert hall?

Answer 1

you do 18+20+22+24+26+28+30+32+34+36+38+40+42+44+46

Explanation:

there are 480 chairs