During lunch one day at Los Alamos, Richard Feynman told his colleagues, “I can work out in sixty seconds the answer to any problem that anybody can state in ten seconds, to 10 percent!”

He had completed several challenges when mathematician Paul Olum walked past.

‘Hey, Paul!’ they call out. ‘Feynman’s terrific! We give him a problem that can be stated in ten seconds, and in a minute he gets the answer to 10 percent. Why don’t you give him one?’

Without hardly stopping, he says, ‘The tangent of 10 to the 100th.’

“I was sunk: you have to divide by pi to 100 decimal places! It was hopeless. … He was a very smart fellow.”

(From Surely You’re Joking, Mr. Feynman!, 1985.)