MAY - JUNE 2009

In this month's brain teasers are all from the book The Man Who Counted about which I have written in my Editorial. I am not giving the answers here. I have given the page number. You can read the book by clicking on The Man Who Counted and storing it in your PC.. I can assure you that it is an excellent book to read and enjoy.

1.) “We are brothers,” the oldest explained, “And we received thirty-five camels as our inheritance. According to the express wishes of my father half of them belong to me, one- third to my brother Hamed, and one-ninth to Harim, the youngest. Nevertheless we do not know how to make the division, and whatever one of us suggests the other two disputes. Of the solutions tried so far, none have been acceptable. If half of 35 is 17.5 if neither one-third nor one-ninth of this amount is a precise-number, then how can we make the division?” (For solution, read from page 5)

2.) “This man,” old Salim said pointing to the jeweler “came from Syria to sell precious stones in Baghdad. He promised he would pay 20 dinars for his lodgings if he sold all of his jewels for 100 dinars and 35 dinars if he sold them for 200. After several days of wandering about, he ended up selling all of them for 140 dinars. How much does he owe me according to our agreement?” (For solution, read from page 11)

3.) “It is not the turban that interests me,” replied Beremiz. “Did you notice that this shop is called The Four Fours. This is a coincidence of unusual importance.”
“A coincidence? Why?”
“The name of this business recalls one of the wonders of calculus: using four fours, we can get any number whatsoever.”
(For solution, read from page 16)

4.) The sheik addressed the three of them: “Here is the esteemed master calculator.” And. to Beremiz he added, “Here are my three friends. They are sheep rearers from Damascus. They are facing one of the strangest problems I have come across. It is this as payment for a small flock of sheep they received here in Baghdad, a quantity of excellent wine, in 21 identical casks:

7 full
7 half-full
7 empty

They want to divide so that each receives the same number of casks and the same quantity of wine. Dividing up the casks is easy—each would receive 7. The difficulty, as I understand it is in dividing the wine without opening them, leaving them just as they are. Now, calculator, is it possible to find a satisfactory answer to this problem?”
(For solution, read from page 20)

5.) “And what do you mean by a perfect number?” the poet asked. “What makes a number perfect?”
(For solution, read from page 27)

6.) “Friendship occurs also among numbers. You will ask, no doubt, how to recognize among numbers those bound together in mathematical friendship. How can geometry distinguish in a numerical series those that are so bound?
(For solution, read from page 38)

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