Answers to the Creative Quiz

In  a post I did in November about creative thinking I offered 5 mental challenges. Here are the answers.

Challenge # 1

Add a single line to the following equation to make it correct but you are not allowed to change the equal sign to an inequality.



10 To 11

Challenge #2

Joanna and Jill share exactly the same birthday and birth year. They also have the same parents but they are not twins. How can that be possible?


They are members of a triplet.

Challenge #3

A man has married 8 different people in the same town.  All are still alive and he never divorced any of them. Polygamy is unlawful but the man has not broken the law. How is this possible?


The man is a wedding celebrant.

Challenge #4

A man walked into an antiques shop and offers to sell what appears to be an extraordinarily old and beautiful bronze coin. On one side there is an image of a Roman Emperor’s head, while the other side shows the date as 500 B.C. The dealer instantly knows that the coin does not date back to 500 B.C. Why?


It could not have been minted any time B.C. because Christ had not been born at the time.

The challenges I presented above all came from a fascinating book written by Richard Wiseman called 59 Seconds: Think a Little, Change a Lot. I really like the fact that it is a self development book that draws on hard science. It’s well worth reading.

Challenge #5

A man is standing on his driveway with his Creditor to whom he owes a large sum of money. It is a time when failure to pay your debt meant imprisonment until the debt was paid. The Creditor being a fair man wanted to marry the Debtor’s beautiful daughter so he proposed a bargain.

The driveway they were standing on was covered by black and white pebbles. The Creditor proposed that he put one black one and one white pebble in a small empty soft money pouch he had in his possession. The Debtor was then to pick a pebble from the pouch and if it was white the debt would be forgiven. But if he drew the black pebble, he would either pay the debt immediately or go to prison unless he gave his permission for the Creditor to marry his daughter. Neither of these choices are what the Debtor wanted.

Believing he had nothing to lose, the Debtor agreed to the proposal but when the Creditor selected the pebbles and put them in the pouch the Debtor noticed that he had intentionally chosen 2 black ones and could not therefore lose the bet! Sensing that if he told the Creditor he was a cheat he would end up in jail anyway.

What strategy could he employ that would guarantee that he, the Debtor, won the bet?


This is a particularly interesting mind game because it illustrates how creative thinking can actually turn what might appear to be a certain negative into a certain positive outcome simply by letting go of established thoughts relating to a given situation.

Here’s the answer … the Debtor, would seem to be in an impossible situation because both stones in the pouch were black! If he raised the issue with the creditor he may well have been told the bet is off, you go to prison or the best case might be the creditor apologized for his “error” and they started over with two different colored stones and so the debtor only had a 50% change of winning the bet.

But here’s how he could have guaranteed himself to win. He would simply take a stone from the pouch and before anyone saw its color, immediately drop it on the driveway which, you’ll recall, is a mixture of black and white pebbles. He would then say “sorry I dropped it but that’s OK because the stone left in the bag must have been the opposite color to the one I dropped.”  The creditor’s only option was to accept the outcome or confess to his dishonesty.

 This mind game came from a Philosophy class I took at College many years ago.