Simple countdown number problem

[Gerben42]

Given how proficient you all are with big numbers, I will just post one with very small numbers.

 

(1 3 4 6) to make 24.

 

Don't post the answer too soon, pls.

 

This problem belongs to the "don't give this problem to your bridge partner before a major tournament" category.

[EricK]

I assume we must use all four numbers:)

In that case:

 

6/(1-3/4)

 

[gwnn]

very simple one. hidden:

 

 

1^3*4*6

 

[helene_t]

With Roman numbers:

 

IV and VI combine to IX by rotating VI 180 degrees and put it underneath.

 

Now (IX-I)*III = XXIV.

[vuroth]

I agree with Gwynn's solution.

[Gerben42]

very simple one.

 

1^3*4*6

 

Sorry, but "^" is not allowed, only + - x /

 

I like Helene's solution!

[gwnn]

i am not Gwynn.

 

oh well in that case I will have to pretend I could have found Eric's solution!

[bb79]

I had put this problem on my website and after a few months, somebody sent me an email saying "i even wrote a C program to try to solve this, I'm sure there is no solution, your question is wrong !?!??!?" :)

 

another similar but less difficult problem is to reach 100 using 1, 7, 7, 7, 7.

 

A difficult problem is to reach 6 using two 1's. But in this problem, you can use any mathematical signs additional to operations, like factorial sign, or square root etc (needs a bit creativity)

[helene_t]

(random nonsense deleted)

[bb79]

I think there are many solution if you include trig functions etc .. also something like : (cardinality(powerset({1}))+1)! :)

 

 

the solution I was thinking contains only math signs (no trig functions). also let's say an average high school student should be able to evaluate the expression :)

[TimG]

also let's say an average high school student should be able to evaluate the expression :)

Average high school student from what country?

[Echognome]

also let's say an average high school student should be able to evaluate the expression :)

Average high school student from what country?

Given worldwide populations, it reasons that the "average" high school student will come from China or India. :)

[EricK]

A difficult problem is to reach 6 using two 1's. But in this problem, you can use any mathematical signs additional to operations, like factorial sign, or square root etc (needs a bit creativity)

I think the solution is:

 

the factorial of the square root of (1 divided point 1 recurring) - sorry I can't do the math's symbols!

 

T oexplain, in case it's not clear, point 1 recurring is equal to 1/9; 1 over that is 9; the square root of that is 3; and 3 factorial is 6.

 

[han]

If "square root" is allowed then this should be correct as well: (1 + 1) times three.

[Guest Jlall]

I couldn't get this lol. Nice problem.

[frouu]

A difficult problem is to reach 6 using two 1's. But in this problem, you can use any mathematical signs additional to operations, like factorial sign, or square root etc (needs a bit creativity)

I think the solution is:

[HIDDEN]

nice solution ! :D

[bb79]

Yes EricK's answer was the one I was hoping one would find. Congrats!

I know the question is a bit illposed. by an average high school student, I meant there's no need for fancy math signs/functions. Sorry if it confused some people here, I wish could have explained more clearly.

[vuroth]

i am not Gwynn.

Sorry about that. :P