### Home > A2C > Chapter Ch2 > Lesson 2.1.3 > Problem2-39

2-39.
1. Lona received a stamp collection from her grandmother. The collection is in a leather book and currently has 120 stamps. Lona joined a stamp club, which sends her 12 new stamps each month. The stamp book holds a maximum of 500 stamps. Homework Help ✎

1. Complete the table below.

Month

Stamps

0

120

1

132

2

3

4

5

2. How many stamps will Lona have after one year?

3. Write an equation to represent the total number of stamps that Lona has in her collection after n months. Let the total be represented by t(n).

4. Solve your equation for n when t(n) = 500. Will Lona be able to fill her book exactly with no stamps remaining? How do you know? When will the book be filled?

Continue adding 12 to find months 2-5.

See part (a). (Continue until month twelve.)

Remember that the initial amount was 120 stamps and the rate is 12 stamps per month.

Use these values to make an equation.

t(n) = 120 +12n

Substitute 500 for t(n).

500 = 120 + 12n

Solve for n.

$\textit{n}=31\frac{2}{3}$

Lona will not be able to fill her book exactly, with no leftover stamps, because when the equation is solved for n, the result is a mixed number. It will be filled in 32 months.