Question

Juan bought a desktop computer and a laptop computer. Before finance charges, the laptop costs $300 more than the desktop. He paid for the computers using two different financing plans. For the desktop the interest rate was 6% per year, and for the laptop it was 7% per year. The total finance charges for one year were $398. How much did each computer cost before finance charges?

Answer 1

The cost of each computer before finance is:

Desktop: $2900.00, Laptop: $3200.00

Explanation:

Lets say the cost of Desktop is 'D' dollars.

The cost of laptop is
`=D+300` dollars.

Total finance charge for 1 year is given by:

`0.06* D+0.07 * (D+300)=398`

Solving for D we get:

`0.06D+0.07D+21=398`.......(equation 1)

`0.13D=398-21=377`

`D=(377)/(0.13) =2900`

Now the cost of laptop is D+300:

`D+300=2900+300=3200`

So before finance, the cost of desktop was $2900.00 and the cost of laptop was $3200.00.

P.S: You can check if your calculation is correct by plugging the values of the cost of laptop and desktop in the equation 1.