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Friday Puzzler -- two dozen

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Friday Puzzler -- two dozen

#1

Friday Puzzler -- two dozen

Alex Y

How many ways can you write a mathematical expression that equals 24, using only three instances of the same digit?

Re: Friday Puzzler -- two dozen

#2

Here are three

Larry Barrett

8+8+8

3^3-3

4!+4-4

Re: Friday Puzzler -- two dozen

#3

good start

Alex Y

And I don't know how many there are. But one of yours suggests another:

4!*4/4

Re: Friday Puzzler -- two dozen

#4

Re: Friday Puzzler -- two dozen

Henry Higginbotham

5P5/5

Okay, I don't know how to make a subscript on this forum. :(

Re: Friday Puzzler -- two dozen

#5

Re: Friday Puzzler -- two dozen

Alex Y

spell it out. I don't understand what your formula is.

Re: Friday Puzzler -- two dozen

#6

Re: Friday Puzzler -- two dozen

Henry Higginbotham

Permutation of 5 items from a set of 5 = 120, divided by 5 = 24.

At least, that's what I had in mind. My math background falls far short of most of the regulars here. Feel free to flunk me -- wouldn't be the first time! :D

Re: Friday Puzzler -- two dozen

#7

Another, maybe

Henry Higginbotham

Now I'm even more out of my comfort zone regarding symbols on this forum, so I've had to screen capture it from CAD. You may have to look closely.


Re: Friday Puzzler -- two dozen

#8

Re: Friday Puzzler -- two dozen

Alex Y

Very good. Should have thought of that interpretation.

Re: Friday Puzzler -- two dozen

#9

Excellent!

Alex Y

You guys are coming up with ones I have not seen before.

Re: Friday Puzzler -- two dozen

#10

Looking for another

Alex Y

that uses only the basic four arithmetic operators (and not all of them).

Hint: All of the solutions offered so far conform with a condition that is NOT a requirement of this puzzle. The solution I am thinking of violates the requirement you might have incorrectly inferred.

Re: Friday Puzzler -- two dozen

#11

Re: Looking for another

Henry Higginbotham

Except for these variations on already stated themes, I'm ready to throw in the towel.

3! x 3 + 3!

4! x 4 / 4

8 + 8 - (-8)

-(-8 - 8 - 8 )

. . . etc.

Unless you mean we're freed from assuming the 24 is Base 10. If Base 7, then:

6+6+6

Re: Friday Puzzler -- two dozen

#12

Nice solution

Alex Y

And you are right, I did not specify base 10.

There is another solution in base 10.

Re: Friday Puzzler -- two dozen

#14

That's the one I was looking for!

Alex Y

"three instances of the same digit" is a slightly less restrictive requirement than "three instances of the same one-digit number"

Re: Friday Puzzler -- two dozen

#15

Good going Henry! 


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