The Mighty Houdini and Cracking PIN Numbers

And, so, Harry Houdini takes to the stage,

“I need a volunteer from the audience”,

Bob puts his hand up, and is chosen, and joins Houdini on the stage, “My name is Bob.” Houdini then says,

“From my brain waves, I have determined the PIN numbers for the bank cards for everyone in the audience, and I will demonstrate this by revealing Bob’s…