A used car was purchased in July 2000 for $11,900. If the car depreciates 13% of its value each year, what is the value of the car, to the nearest hundred dollars, in July 2003?

1 Answer
Jan 8, 2018

#$7200# to nearest $100 dollars

Explanation:

Original value depreciates by 13% annually. So for the 1st year, we have:

#$11900-$11900xx13/100=$10353#

#->11900xx1-11900xx0.13color(white)(88)#( 0.13 is 13% as a decimal )

Factoring:

#->11900(1-0.13)=>11900xx0.87#

For the 2nd year:

#10353xx0.87=907.11#

For the 3rd year:

#907.11xx0.87=7836.1857#

So this is following the pattern:

#11900xx0.87->10353xx0.87->907.11xx0.87#

This is the same as:

#11900xx0.87xx0.87xx0.87=>11900(0.87)^3#

This is for 3 years, so for #n# years:

#:.#

#11900(0.87)^n#

Since #0.87=(1-0.13)#, we have:

#11900(1-0.13)^n#

From this we can derive the formula:

#FV=PV(1-R)^n#

#FV= #Future Value

#PV=#Present Value

#r=# interest rate as a decimal

#n=# number of years

For the original problem:

#PV=11900#

#r=0.13#

#n=3 7/12=43/12#

#FV=11900(1-0.13)^(43/12)=7224.774281#

#$7200# to nearest $100 dollars