if the item was 65% off, then you can see that 80$ is 35% of the original price (subtracting 65% from 100% will give you 35%). you should now have 80/x = 35/100. multiplying both sides by 100 (to isolate the 35 and make it easier), and then dividing both sides by 35 (to cancel things out), you will get about 228 (228.57 or so)