Question: James buys $3000 worth of stuff from Amazon.  He has to return a TV that cost $700 and a bike that cost $500.  He also sells another bike that cost 20% more than the bike he returned for 80% of what he bought it for.  He then buys a toaster for $100.  How much is he out of pocket for everything?
Solution:
The items he returned were valued at $700 + $500 = $1200
So far he is out 3000-1200 = 1800 after recouping 1200.
An item that is 20% more expensive cost 1 + .2 = 1.2 times as much as the item
So that means the bike he sold cost $500 * 1.2 = $600
He sold it for $600 * .8 = $480
From the bike that he had bought for 600, he was out 600-480 =120
So far he is out 1800+120 = 1920
If he also bought a toaster worth 100, he was out 1920+100 = 2020
Answer: 2020