Harper buys a car in 2007 for $20000. Each year,the car decreases in value by 18%. How much will the car be worth in 2012? round to the nearest cent

Question

Is the common ratio 0.18? If not please help me

Answer 1

No
Think of how you would obtain the next term
you could take .18 of the previous term and subtract or just take .82 of it

so the sequence is:
20000 , 20000(.82), 20000(.82)^2 , ....
so r = .82

I am sure you can now answer the question