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GeneralRe: Not on MY watch! Pin
Corporal Agarn24-Jan-12 4:15
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GeneralRe: Not on MY watch! Pin
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GeneralRe: Not on MY watch! Pin
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GeneralIQ / Programming Quiz (Cannon-Ball Stacks) Pin
AspDotNetDev23-Jan-12 20:34
protectorAspDotNetDev23-Jan-12 20:34 

Background



I'm reading "The Mammoth Book of IQ Puzzles". It contains, as you may have guessed, a bunch of IQ puzzles. I just solved one of them and thought I'd write the problem down here so you would all have a chance to solve it too. It is called "Cannon-Ball Stacks". In finding the answer, reference materials, books, calculators, and computers are allowed. Since computers are allowed, programs can be created to get the solution.

Cannon-Ball Stacks



A park ranger has stacked cannon-balls in two tetrahedral pyramids for display at Gettysburg. He later decides to combine the cannon-balls in both of the pyramids in order to create one large pyramid. The smallest number of cannon-balls he can have if the two pyramids are the same size is twenty (assuming he uses every cannon-ball in both pyramids).

[10 cannon-ball pyramid] + [10 cannon-ball pyramid] = [20 cannon-ball pyramid]


If the two smaller pyramids are different sizes, however, what would be the minimum number of cannon-balls he could use to make one large tetrahedral pyramid?

Difficulty: 4 out of 5.

AspDotNetDev's Extra Rules


Explain how you arrived at the solution. If you create a program to help you solve the problem, paste that in your message. I will reply to this message with the answer in a hidden <span> tag. Don't cheat by looking first though! I will post tomorrow how I arrived at my solution (which may be incorrect, as the book doesn't list what the correct answer is). Points will be awarded for: elegance, quickness, humor, and correcting others (in no particular order).

Good luck!

AnswerAnswer Pin
AspDotNetDev23-Jan-12 20:36
protectorAspDotNetDev23-Jan-12 20:36 
GeneralRe: IQ / Programming Quiz (Cannon-Ball Stacks) Pin
Mark_Wallace23-Jan-12 20:48
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AspDotNetDev23-Jan-12 20:53
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GeneralRe: IQ / Programming Quiz (Cannon-Ball Stacks) Pin
AspDotNetDev23-Jan-12 20:54
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AspDotNetDev23-Jan-12 20:59
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GeneralRe: IQ / Programming Quiz (Cannon-Ball Stacks) Pin
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GeneralRe: IQ / Programming Quiz (Cannon-Ball Stacks) Pin
AspDotNetDev23-Jan-12 21:20
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GeneralRe: IQ / Programming Quiz (Cannon-Ball Stacks) Pin
Mark_Wallace23-Jan-12 21:27
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GeneralRe: IQ / Programming Quiz (Cannon-Ball Stacks) Pin
AspDotNetDev23-Jan-12 21:36
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GeneralRe: IQ / Programming Quiz (Cannon-Ball Stacks) Pin
Mark_Wallace23-Jan-12 21:52
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GeneralRe: IQ / Programming Quiz (Cannon-Ball Stacks) Pin
AspDotNetDev23-Jan-12 21:56
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GeneralRe: IQ / Programming Quiz (Cannon-Ball Stacks) Pin
PhilLenoir25-Jan-12 5:18
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GeneralRe: IQ / Programming Quiz (Cannon-Ball Stacks) Pin
Super Lloyd23-Jan-12 20:59
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GeneralRe: IQ / Programming Quiz (Cannon-Ball Stacks) Pin
AspDotNetDev23-Jan-12 21:01
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GeneralRe: IQ / Programming Quiz (Cannon-Ball Stacks) Pin
Super Lloyd23-Jan-12 21:02
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AspDotNetDev23-Jan-12 21:03
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