first thing about percentage problems think either decimals or factions.
Decimals if your teacher is nice and lets you use a calculator.
.15*329=$49.35 will be taken off the original price
$329.00-$49.35=$279.65 new discounted price
Now for the fractional version if you like factions:
x/$329.00 = 15/100
Let's cross and multiply then divide
look it just like the decimals then you would subtract
$320.00-$49.35=$279.65 discounted price
do it yourself