Jake amasses a fortune of 80 bitcoin.  He donates 20 bitcoins to charity.  He then gives half of all the bitcoins to his brother.  After that, he triples the number of bitcoins he has.  Then he donates another 10 coins.  How many coins does he have?
He had 80-20=<<80-20=60>>60 after the donation
He kept 60/2=<<60/2=30>>30 after giving half to his brother
So he has 30*3=<<30*3=90>>90 coins
He then does 1 more donation and has 90-10=<<90-10=80>>80 coins left
#### 80