Tek-Tips is the largest IT community on the Internet today!
Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!
-
Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!
Mathcad for brainteaser
- Thread starter jackboot
- Start date
GregLocock
Automotive
Not easily.
You'd be better off writing a program in a language that supports EVAL or equivalent, that creates equations with valid syntax and then works out the result.
You'd also have to be very careful about defining your precedence rules, if brackets are not permitted.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
You'd be better off writing a program in a language that supports EVAL or equivalent, that creates equations with valid syntax and then works out the result.
You'd also have to be very careful about defining your precedence rules, if brackets are not permitted.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
GregLocock
Automotive
RPN?
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
ChrMeissner
Mechanical
Hello,
are you sure, it works? I wrote it in MathCAD and didn't find a solution. It wasn't "easy" (@GregLocock) but it works. There are 1536 posibilities, no one is doubled and there is no equation with the result 24 (if my program works right).
You find the program as PDF at my website:
I havn't time enough to check the whole code for mistakes, even I can't endure that a teenager get the solution.
Christian.
are you sure, it works? I wrote it in MathCAD and didn't find a solution. It wasn't "easy" (@GregLocock) but it works. There are 1536 posibilities, no one is doubled and there is no equation with the result 24 (if my program works right).
You find the program as PDF at my website:
I havn't time enough to check the whole code for mistakes, even I can't endure that a teenager get the solution.
Christian.
- Thread starter
- #8
This is the address to the math teaser.
It says:
24 - Arithmetic - Hard
Using each of the numbers 1,3,4,6 create an expression which evaluates to 24. You may use any of the four standard arithmetic operations *,+,-,/ and parenthesis. You must use each of the numbers exactly once. You need not use any other numbers. It can also be done with 3,3,8,8.
It is supposed to have a solution unless it is just a joke.
jackboot
- Thread starter
- #9
GregLocock
Automotive
Christian - I agree with jackboot. my eyes glazed over.
Jackboot, if you can understand Christians' sheet then use that.
Otherwise I'd define a syntax, that all parentheses must be used. Then I'd write all the legal patterns, where i is an integer and o is an operator
((ioi)o(ioi))
(io(io(ioi)))
(((ioi)oi)oi)
((io(ioi))oi)
(io((ioi)oi))
is that all there are?
make the appropriate substitutions and you should get there.
I make the total number of combinations 5*(4*3*2*1)*4*4*4=
7680, of which many are no doubt dupes, since + and * are commutative.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
Jackboot, if you can understand Christians' sheet then use that.
Otherwise I'd define a syntax, that all parentheses must be used. Then I'd write all the legal patterns, where i is an integer and o is an operator
((ioi)o(ioi))
(io(io(ioi)))
(((ioi)oi)oi)
((io(ioi))oi)
(io((ioi)oi))
is that all there are?
make the appropriate substitutions and you should get there.
I make the total number of combinations 5*(4*3*2*1)*4*4*4=
7680, of which many are no doubt dupes, since + and * are commutative.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
ChrMeissner
Mechanical
@meintsi:
You forgot that the original question was WITHOUT brackets (zdas04 from Apr 7). Based on that statement I wrote the program. But I've actual no time to change it working with brackets.
Christian.
You forgot that the original question was WITHOUT brackets (zdas04 from Apr 7). Based on that statement I wrote the program. But I've actual no time to change it working with brackets.
Christian.
- Thread starter
- #13
Where does this say that brackets are not permitted?
And if you read the author's second post from 11 Apr 05 11:56}, I repeat...
"This is the address to the math teaser.
It says:
24 - Arithmetic - Hard
Using each of the numbers 1,3,4,6 create an expression which evaluates to 24. You may use any of the four standard arithmetic operations *,+,-,/ and parenthesis. You must use each of the numbers exactly once. You need not use any other numbers. It can also be done with 3,3,8,8.
It is supposed to have a solution unless it is just a joke."
Remember...
[navy]"If you don't use your head,[/navy]![[idea]](/data/assets/smilies/idea.gif "[idea] [idea]")
[navy]your going to have to use your feet."[/navy]
And if you read the author's second post from 11 Apr 05 11:56}, I repeat...
"This is the address to the math teaser.
It says:
24 - Arithmetic - Hard
Using each of the numbers 1,3,4,6 create an expression which evaluates to 24. You may use any of the four standard arithmetic operations *,+,-,/ and parenthesis. You must use each of the numbers exactly once. You need not use any other numbers. It can also be done with 3,3,8,8.
It is supposed to have a solution unless it is just a joke."
Remember...
[navy]"If you don't use your head,[/navy]
[navy]your going to have to use your feet."[/navy]
This is a very old and often asked problem.
Solutions sets also include
1237 1334 1467 1555 1569 1668
2258 2469 4778 5668 5788
But the hardest one is to solve is....
Obtain an expression which equals 24.
Using the numbers 4 7 7 9
Using + - x / .
Remember...
[navy]"If you don't use your head,[/navy]
[navy]your going to have to use your feet."[/navy]
Solutions sets also include
1237 1334 1467 1555 1569 1668
2258 2469 4778 5668 5788
But the hardest one is to solve is....
Obtain an expression which equals 24.
Using the numbers 4 7 7 9
Using + - x / .
Remember...
[navy]"If you don't use your head,[/navy]
[navy]your going to have to use your feet."[/navy]
- Status
Similar threads
- Locked
- Question
