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Archive for July, 2011

## No Card Game I Know Of!

Posted by Karl Sharman under Tom (7 Responds)

You have a hand of cards that depict each of the letters of the alphabet. You fan the cards and see they are in the following order:
F, W, X, Y, Z, K, L, A, T, U, J, N, O, S, D, E, P, V, C, B, G, H, I, Q, R, M

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## The Second Series (actually, probably 10th or 11th..)

Posted by Karl Sharman under Tom (4 Responds)

Consider this series:
4, 5, 8, 8, 9, 9, 12, 13, 13, 13, 17, 18, …, …, …
What would the 50th, 63rd and 100th observations be?

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## A Sliding Probability

Posted by Karl Sharman under Tom (18 Responds)

For your next experiment, you have managed to round up an infinite number (give or take) of willing test subjects.
You also have a big slide with 100 holes in it.
As each of your test subjects go down the slide, they have a 50/50 chance of either going down the holes, or continuing down the [...]

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## Your Next Deal With The Devil – It’s 50/50….?

Posted by Karl Sharman under Tom (22 Responds)

I show you a shuffled deck of standard playing cards, one card at a time, no Jokers in the pack.
At any point before I run out of cards, you must say “RED!”.
If the next card I show is red (i.e. diamonds or hearts), you win.
As “dealer” I don’t have any control [...]

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## Maths Challenge 9

Posted by Chris under Mathemagic, MathsChallenge (23 Responds)

An investor puts \$10,000 into a weekly trading scheme.
In each week it is equally likely that he’ll make an 80% gain or a 60% loss (there are no other possibilities). One year later (52 weeks), roughly how much money does the investor expect to have?  The answer is one of the following:
a) \$1.95, b) \$14,000, c) \$140,000, [...]

## Maths Challenge 8

Posted by Chris under Mathemagic, MathsChallenge (9 Responds)

Prove that for any natural number that ends in 1, 3, 7 or 9, that it has an infinite number of multiples which consists only of a string of 1’s.
e.g. 13*8547 = 111111
NB It is trivial to show that numbers ending in 0, 2, 4, 5, 6 or 8 cannot possses that property.

## Don’t Try This With Full Pint Glasses

Posted by Karl Sharman under Tom (31 Responds)

Four glasses are placed upside down in the four corners of a square
rotating table.
You wish to turn them all up. You may do so by grasping any two glasses and, optionally, turning either over.
There are two catches:
1. you are blindfolded
2. the table is spun after each time you move the glasses
Assuming that a bell [...]

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## A Deal with the Devil for £163m

Posted by Karl Sharman under Tom (37 Responds)

You have made a deal with the devil… You will win the lottery if you can decide the optimal position in the queue to buy the £163m Euromillions winning lottery ticket.
There are some conditions. Ain’t that always the way when making this sort of deal!
You will win, if your position in the queue is [...]

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## It’s Sequence Time Again

Posted by Karl Sharman under Tom (13 Responds)

The following sequence has a name…..but I don’t know what that is…. What’s the next number in the meantime….
2
12
360
75600
174636000

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## Mathematical Proof Required

Posted by Karl Sharman under Tom (22 Responds)

What unknown value can you add to 1 in order to get one less?

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