Sara agrees to buy a car for a down payment of $3000 and payments of $315 per month for 4 years. If the interest rate is 4.25% per year, compounded monthly, what is the actual purchase price of the car?

1 Answer
Nov 25, 2016

color(brown)("Full pre interest price "=$15760.00)

Explanation:

color(blue)("Down payment")

color(blue)($3000)

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color(blue)("Determine the selling price above the down payment")

Let the actual selling price after down payment be P

Annual interest is 4.25/100

Split over 12 months this is 4.25/1200 per monthly payment

4 years is 4xx12 = 48 months

So we have:

P(1+4.25/1200)^(48)=$315xx12xx4

log(P)+48log(1+4.25/1200) = log(15120)

color(blue)(=>P = $12760.04)

There is scope for a slight difference due to inherent errors in calculator algorithms.
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color(blue)("Determine total price pre interest")

$12760.04" "+" "$3000" "=" "$15760.04

Due to anticipated errors in the calculator round this to:

color(brown)($15760.00)