Last year my math book cost $126, and i was told the price would increase 9% each year. If the cost continues to increase at this rate, what will my math book cost two years from now when i graduate? show your work.

Question

Mathematics

Crystal Wilson

1 March, 07:21

Last year my math book cost $126, and i was told the price would increase 9% each year. If the cost continues to increase at this rate, what will my math book cost two years from now when i graduate? show your work.

+2

Answers (2)

Know the Answer?

Alonso Barr · Answer 1

It's a geometric sequence.

an=a1*r^ (n-1)

a1=126

r=109%

an=126 * (109%) ^ (n-1)

substitute n with 3 (because in year 0 n will be 1, in year 1 n will be 2, and so on)

a3=126 * (109%) ^ (3-1)

a3=149.7$

Brooklynn · Answer 2

2,268 because u have to add the 2 years with 126