1. ## Weird puzzle

Found this:

12-7*6+19-14=11
Add brackets only (no limit) so above is correct.

I can't do it...

2. ## Re: Weird puzzle

did you get an answer whether splitting numbers, ala 19 -> (1)(9), was legit?

3. ## Re: Weird puzzle

Could the RHS be 1, ie (1)(1), rather than 11?

4. ## Re: Weird puzzle

I simply don't know...
The fact that * is used for multiplication in the problem seems to eliminate (1)(9).

Found this site which "apparently" solved it...but can't join the damn place:

https://www.chegg.com/homework-help/...laces-q7371809

5. ## Re: Weird puzzle

Originally Posted by DenisB
I simply don't know...
The fact that * is used for multiplication in the problem seems to eliminate (1)(9).

Found this site which "apparently" solved it...but can't join the damn place:

https://www.chegg.com/homework-help/...laces-q7371809
They've heard of you, huh?

-Dan

6. ## Re: Weird puzzle

Well, why don't you guys try and join....!!

7. ## Re: Weird puzzle

It seems you have to pay! Not doing that.

8. ## Re: Weird puzzle

Originally Posted by DenisB
Found this:

12-7*6+19-14=11
Add brackets only (no limit) so above is correct.

I can't do it...
There are $14$ ways to parenthesize the expression $12-7*6+19-14$

If none of them give $11$ as the answer then this is a trick question

9. ## Re: Weird puzzle

Originally Posted by Idea
There are 14 ways to parenthesize the expression 12−7∗6+19−14
Including nested parenthesizing?

10. ## Re: Weird puzzle

these are the 14 ways in which the expression can be calculated

$\displaystyle 12-(7*(6+(19-14))),$
$\displaystyle 12-(7*((6+19)-14)),$
$\displaystyle 12-((7*6)+(19-14)),$
$\displaystyle 12-((7*(6+19))-14),$
$\displaystyle 12-(((7*6)+19)-14),$
$\displaystyle (12-7)*(6+(19-14)),$
$\displaystyle (12-7)*((6+19)-14),$
$\displaystyle (12-(7*6))+(19-14),$
$\displaystyle ((12-7)*6)+(19-14),$
$\displaystyle (12-(7*(6+19)))-14,$
$\displaystyle (12-((7*6)+19))-14,$
$\displaystyle ((12-7)*(6+19))-14,$
$\displaystyle ((12-(7*6))+19)-14,$
$\displaystyle (((12-7)*6)+19)-14$

14 is the $\displaystyle 4^{th}$ Catalan number
(there are 4 operations in the given expression and 5 operands)

and the 14 possible values

$\displaystyle \{-65,-65,-35,-149,-35,55,55,-25,35,-177,-63,111,-25,35\}$

11 does not appear in the list (but there is a 111)

11. ## Re: Weird puzzle

Originally Posted by Idea
11 does not appear in the list (but there is a 111)
Thanks...I at least got the "111"!!

12. ## Re: Weird puzzle

Have you tried it where you can split the 2-digit numbers with a left or right bracket? Or where the RHS is (1)(1) = 1 rather than 11.