Riddle

[micro]

You have 12 sacs ABCDEFGHIJKL

(1) Weigh ABCD against CDEF

...

A really good and straightforward explanation.
You probably just wanted to write 'Weigh ABCD against EFGH'.

[Fons]

What about this one:




How to slice an APPLE PIE in 8 PIECES OF THE SAME SIZE. (YOU CAN ONLY SLICE 3 TIMES!!)

[Fons]

no-one?

[lazza]

What about this one:




How to slice an APPLE PIE in 8 PIECES OF THE SAME SIZE. (YOU CAN ONLY SLICE 3 TIMES!!)

I asuume you can't put any pieces on top of each other....

[androl]

1)
APPL | EPIE

2)
AP | PL
EP | IE

3)
A | P
E | P
P | L
I | E

[Fons]

What about this one:




How to slice an APPLE PIE in 8 PIECES OF THE SAME SIZE. (YOU CAN ONLY SLICE 3 TIMES!!)

I asuume you can't put any pieces on top of each other....

Well...... actually..... you can (humans have hands to lift sliced pieces up) But you don't have to make a tower or something like that

[Dakkus]

To clear it up, here's an apple pie that isn't very long and narrow:

Original situation:
APPL
EPIE

Slice the piece into two halves
AP | PL
EP | IE

Slice the halves. Although they are two different parts, you can slice them with one slice if you keep them next to each other.
AP | PL
---------
EP | IE

Now you'll have to move the pieces on the table (however, you don't need to put them on top of each others, just in a row)

This is what the pie will look like:
AP
---
PL
---
EP
---
IE
---

Now you only have to slice all of these pieces into two pieces with one vertical slicing:
A | P
---|---
P | L
---|---
E | P
---|---
I | E

TA-DAA!

This works also with a round apple pie.
You just need to rotate the 1/4 pieces 45 degrees so that their corner is on the last slicing line.

It'll look about this way:

../\
./..\
/....\
'~~'

../\
./..\
/....\
'~~'

.../\
../..\
./....\
'~~'

.../\
../..\
./....\
'~~'

And then you just slice them all at once.

[Fons]

I would have done it without moving the pieces

[Burdie]

I would have done it without moving the pieces

I thought we had to devide an apple in 8 pieces and that is easy. My mother did this already when i was a kid

principe stays the same: put the knife in the middle and make an horizontal cut. Make the same kind of cut only in an angle of 90 degrees.
Than cut the pie in a vertical direction.

I think the last cut makes a lot off mess but we have now 8 pieces

[androl]

but if you do it that way, 4 pieces are different because they contain the apples, while 4 pieces contain the lower part of the pie

[lazza]

If it's a round pie, you make a circular cut 1/sqrt2 of the distance from the centre, then make two straight cuts through the middle at 90degrees to each other. But then the people who get the outside portions get more crust....

[Dakkus]

If it's a round pie, you make a circular cut 1/sqrt2 of the distance from the centre, then make two straight cuts through the middle at 90degrees to each other. But then the people who get the outside portions get more crust.... :? :? :roll:

But in the other hand, some people like the parts with only the apples on them, some people prefer having something to hold the piece in their hands on the side of the piece. So, that's actually the best way. Caters to everyone. And is pretty darn funky. Although.. Can you really call the first cut "slicing"? :D

[JP Simões]

For the 'sacs of rice' riddle, I found a way which only takes 2 weighings, but depending on the point of view, it can be considered as much as 7 weighings.

Simply put all 12 sacs on the scale, but instead of placing six on the left plate, then six on the right, place them one by one:
#1 on the left plate, then #2 on the right, then #3 on the left, then #4 on the right, and so forth...

You'll notice, by the time the plates are unbalanced, which pair of sacs has the false one (say, #11 and #12)

Then just compare one (#11) with one you know to be normal, like #1. They either weigh the same, and then #12 is the false one, or they don't, then #11 is the false one.


Is this cheating?