SM cinema has 24 seats in the 1st row, and each of the succeeding rows has 2 more seats than the row before it. If there are 16 rows of seats, what is its seating capacity?

Question

SM cinema has 24 seats in the 1st row, and  each of the succeeding rows has 2 more  seats than the row before it. If there are 16  rows of seats, what is its seating capacity?

R_scott · Answer

16th row has ... 24 + (2 * 15) = 54 average row length ... (24 + 54) / 2 capacity is ... number of rows * average row length