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Two fours (or fewer?) (Posted on 2006-04-07) Difficulty: 3 of 5
There is a way to express 64 with only two fours and no symbols beyond +, -, *, /, ^, √, !, and parenthesis, although some may be used more than once. It isn't too hard. Can you find it?

It is asserted in a reliable source that 64 can also be expressed with a single 4 using 57 square root signs, nine factorials (no double or higher factorials), and 18 sets of parentheses. I can't figure it out. Can you?

See The Solution Submitted by Jer    
Rating: 4.0000 (2 votes)

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Unreliable use of reliable source | Comment 13 of 15 |

Looking again, the book says <b>brackets<b> which I incorrectly assumed to be an old way of saying parenthesis.  The reprinted first paragraph shows it actually refers to the greatest integer, or floor function as Demau Senae was correct to assume.

The object is then to apply these three functions in the correct order to obtain 64.
Demau's solution may be right but it is really hard to read.

Would you be willing to list the order of the operations so I can confirm it.  Then I can post it as the 'official solution'


  Posted by Jer on 2006-04-11 12:44:22
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