THINK IT THROUGH – Death by chocolates !

Alex and his girlfriend Betty board a train at the South Yarra Station on their way to downtown Melbourne. Neither of them has a valid ticket. Love can be blinding and before they know it, there is a ticket inspector next to them asking for their tickets. Caught with their pants down(???), they plead guilty of trying to hitch a free ride. The ticket inspector (a retired statistics professor) is authorised to administer a special punishment for this offence.

He brings out a box of 9 identical chocolates, 3 of which are contaminated with a deadly poison. He makes Alex and Betty, in turn choose and immediately eat a single chocolate.

Death by chocolate

Question: Is it in Alex’s best interest to persuade Betty to choose first?

(Question based on an idea taken from “ Grimmett”)

ps: Please sent in your comments, it doesn’t have to be mathematical…..

New section : THINK IT THROUGH! (updated)

Hello, today we open up a small section called: THINK IT THROUGH! You will find interesting problems to ponder and do, here goes :-


Five balls are randomly chosen, without replacement, from an urn that contains 5 red, 6 white and 7 blue balls. Find the probability that at least one ball of each colour is chosen.

Feel free to write in your answers via our comments section below.

We would love to hear from you, cheers.

p/s : Solution coming soon. Try first.


Solution :
[gview file=”think-it-through-solution.pdf” height=”600px” width=”100%”]