Mathematical sequences can be used to model real life applications. Suppose you want to construct a movie theater in your town. The number of seats in each row can be modeled by the formula C_n = 16 + 4n, when n refers to the nth row, and you need 50 rows of seats.

(a) Write the sequence for the number of seats for the first 5 rows

(b) How many seats will be in the last row?

(c) What will be the total number of seats in the theater?

1 answer

a.
C(n)=16+4n
C(1)=16+4(1)=20
C(2)=16+4(2)=24
...
C(5)=16+4(5)=36

b.
C(50)=16+4(50)=?

c.
50
∑ C(i)
i=1

50
∑ 16+4i
i=1

16(50)+4sum(i)
=800 + 4[ 50(1+50)/2 ]
= 800+4(1275)
= 5900