Manuel bought a desktop computer and a laptop computer. Before finance charges, the laptop cost $250 less than the desktop.

Question

Manuel bought a desktop computer and a laptop computer. Before finance charges, the laptop cost $250 less than the desktop. He paid for the computers using two different financing plans. For the desktop the interest rate was 9% per year, and for the laptop it was 6% per year. The total finance charges for one year were $300 . How much did each computer cost before finance charges?

Answer 1

Let x = cost of desktop computer; then x - 250 = cost of laptop computer

 

converting % to decimals, 9% = 0.09 and 6% = 0.06

 

Then, 0.09x + (x - 250)0.06 = $300

0.09x + 0.06x - 15 = $300

0.15x = $315

x = $2100

then x - 250 = $1850

 

Proof: $2100•0.09 + 1850•0.06 = $189 + $111 = $300