Question

Reuben bought a desktop computer and a laptop computer. Before finance charges, the laptop cost $300 less 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 $252. How much did each computer cost before finance charges?

Answer 1

The cost of desktop is
`\$2100` and the laptop is
`\$1800`

Solution:

Let us assume the desktop cost
`\$ x` and laptop costs
`\$ y`

Now, the laptop cost $300 less than the desktop,

So,
`x = y+300` ………… (i)

Again the desktop the interest rate was
`6\%` per year = 0.06x

For the laptop it was
`7\%` per year = 0.07y

The total finance charges for one year were
`\$ 252`

So,
`0.06x + 0.07y = 252`

`0.06 (y +300) +0.07- 252 = 0` (value from (i))

`0.06y + 18 +0.07-252 = 0`

`0.13y =234`

`y = 1800`

Hence
`x = (1800+300) = 2100`

The desktop costs
`\$2100` and the laptop costs
`\$1800`