Today, the crypto quiz will be about BITCOIN. Before you start answering the questions make sure that you have read the rules and the rewards section here. Now, let's go to the questions:
a) proof of stake
b) proof of work
c) proof of elapsed time
a) 5 minutes
b) 10 minutes
c) 60 seconds
a) bitcoins sent to a invalid address so they are lost
b) bitcoins sent to a user called "ghost"
c) bitcoins that are unspent for a long time and probably this is due to the fact that their private keys are lost.