Irish Math

A job interviewer gave an Irishman the following test. He drew 3 pairs of vertical lines on a piece of paper, gave the paper to the Irishman and said, "Could you please show me a clever way to make this into 9?"

After thinking for a while, the Irishman took the pencil and drew a canopy of leaves on top of the 3 pairs of lines, then handed the paper back to the interviewer.

The interviewer looked at the drawings and said, "But that is not 9!"

"Oh, yes, it is," said the Irishman with a broad Irish accent, "Tree + tree + tree make nine!"

The interviewer handed the paper back to the Irishman and asked him to make it 99.

After thinking for a longer while, the Irishman scribbled up and down the trunks and handed the paper back to the interviewer. The interviewer looked at the drawings and said, "But that is not 99!"

"Oh yes it is," said the Irishman, "Dirty tree + dirty tree + dirty tree make ninety nine."

The interviewer was now a bit upset so he decided to do the Irishman once and for all. So, he handed the paper back to the Irishman and asked him to make it 100.

After thinking for a considerably longer time, the Irishman suddenly grabbed the pencil and drew a little blop on the bottom right hand side of each tree, then handed the paper back to the interviewer.

The interviewer looked at the drawings and said, "But that is not 100!" "Oh, yes, it most certainly is," said the Irishman with a much broader Irish accent, "Dirty tree and a turd + dirty tree and turd + dirty tree and a turd make 100!"