Problema Solution

A theater has 39 seeats in the first row, 42 seats in the second row, 45 seats in the third row; and so on.

(a)Can the number of seats in each row be modeled by and arithmetic or geometric sequence?

(b) Write the term for a sequence a that gives the number of seats in row

n

n.

(c)How many seats are in row 15?

A. what type of sequence is present?

B.a =

n

C.There are__ seats in row 15.

Answer provided by our tutors

a)      The sequence is arithmetic sequence.

b)      No of seats in nth row is = (n/2)(2a+(n-1)d)

c)       No of seats in 15th row is caluculated by above formula,

Here n=15, a= sets in first row=39, d=(42-39)=3

By substituting seats in first row= (15/2)((2*39)+(3*14))=900

So seats in 15th row=900