Ken's blog

Pierre, the First Mate, was sitting in the mess room of the Nautilus flipping cards from a Tarot deck. He would periodically stop and write some numbers in a small notebook near the cards.

“What are you doing, First Mate?” said Captain Nemo, who had stopped to look as he was walking by on his way to the bridge.

“Sir, I am checking to see how many cards on the average I need to draw from a shuffled Tarot pack before I get an Ace,” said Pierre with a bright smile as he drew The Hanged Man.

“Why don’t you just calculate it? It’s much faster,” grinned Captain Nemo.

“I thought about doing that, but there are so many combinations on how to get an Ace,” moaned Pierre scratching his head as he pulled The Fool.

“Why don’t you think about how not to get an Ace instead,” suggested Captain Nemo, continuing on his way to the bridge.

“Hmm, that’s not a bad idea, Sir,” the First Mate replied and started to write some symbols in his notebook.

What do you figure is the average number of Tarot cards that need to be drawn from a well-shuffled Tarot pack before an Ace appears?