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1) Assume there are 20 nodes in network and all are receiving all transactions. Afterr 10 min they all pick transactions from their transaction pool and start creating a block. Now, will all nodes use the same transactions to create a block, or can each node have different transactions in that particular block?
2) If there are 20 nodes in network and all start creating blocks, what will happen if more then one node creates a block at the same time?