Question

The value of a dirt bike decreases by 30% each year. If you purchased this dirt bike today for $500, to the nearest dollar how much would the bike be worth 5 years later?

Answer 1

This is exponential decay of the form:

f=ir^t, f=final value, i=initial value, r=rate, t=time in this case:

f=500((100-30)/100)^t

f=500(0.7)^t so f(5) is

f(5)=500(0.7)^5

f(5)=$84.035

f(5)=$84.04 to nearest cent