One evening, Jack found Jill sitting at a caf\u00e9 table with her attention riveted on a small, well-worn and water-logged ship\u2019s logbook in her hand.<\/p>\n
\u201cWhat\u2019s up, Jill,\u201d he said cheerfully. \u201cYou look puzzled.\u201d<\/p>\n
\u201cI really am, Jack. My great uncle drowned recently when his sailboat sank in the Aegean Sea near Skiathos, and I\u2019m trying to make sense of a message he wrote in his logbook before sinking regarding my inheritance. They found it floating with him in the sea,\u201d said Jill.<\/p>\n
She gestured for Jack to sit down, calling for the waitress to bring a coffee.<\/p>\n
\u201cSorry about your great uncle, Jill. What\u2019s the message?\u201d asked Jack, sitting down.<\/p>\n
\u201cIt says I have to go to the SchwitzerliBank in Zurich to obtain my inheritance, but I need to give them a special code number to receive it,\u201d said Jill in frustration, pulling on a black hair lock.<\/p>\n
\u201cAnd what\u2019s the number?\u201d asked Jack, preparing his coffee with a spoon.<\/p>\n
\u201cWell, that\u2019s the problem. It\u2019s in some kind of code,\u201d said Jill with a baffled look on her face.<\/p>\n
\u201cExplain, please,\u201d said Jack, taking a careful sip of his hot coffee.<\/p>\n
\u201cOn this page my great uncle says:<\/p>\n
\u2018Move the last to the first of the six, then find the four greater twin and use it,\u2019\u201d <\/em><\/p>\n said Jill, \u201cwhich doesn\u2019t make any sense to me,\u201d she groaned, randomly flipping the pages of the logbook.<\/p>\n \u201cHmm, that really is a mouthful,\u201d said Jack. \u201cSeems your great uncle didn\u2019t want to advertise the number.\u201d<\/p>\n \u201cNo joke. Got any ideas?\u201d Jill looked up at Jack with big green eyes full of hope.<\/p>\n After thinking a while on the strange statement, Jack suddenly got an idea.<\/p>\n \u201cYou have to give a number to the SchwitzerliBank in Zurich to get your inheritance, right? Maybe this is a six-digit number,\u201d said Jack.<\/p>\n \u201cCould be you are right, but what about \u2018\u2026move the last to the first of the six\u2019?\u201d<\/p>\n \u201cHey, maybe the word \u2018twin\u2019 means another number derived from the first,\u201d said Jack enthusiastically.<\/p>\n \u201cIn this case you get it by moving the last digit to the first position.\u201d<\/p>\n \u201cYea, that really makes sense. But what about the \u2018four greater\u2019 part?\u201d<\/p>\n \u201cSeems the second number is four times greater than the first, and since it says \u2018use the twin\u2019 I would guess this is the number to present to the bank,\u201d said Jack.<\/p>\n \u201cGood thinking, Jack. But how do we work out what the twin number is?\u201d<\/p>\n \u201cWell, I\u2019m taking a course in Number Theory and I\u2019m sure I can work it out. So, what will you give me in return,\u201d said Jack with a roguish grin.<\/p>\n \u2018How about dinner at your favorite Hindu restaurant \u2013 followed by some dessert,\u201d said Jill demurely.<\/p>\n \u201cDeal! Give me a pen and a piece of paper, Jill.\u201d<\/p>\n What would you say the number Jill had to give to the SchwitzerliBank in Zurich<\/em> was?<\/em><\/p>\nShare this:<\/h3>