Riddles, brain puzzles and mathematical problems

[BAndrew]

This thread was made for those who like using their wits to solve riddles and problems.

Here's how it's done:

A person posts a riddle/problem and the others are trying to figure out the solution. Whoever founds the solution posts a new riddle* and the same procedure is redone.

*NOTE: If the person can't or doesn't want to post/share a problem after he has solved one then (s)he should simply say so and another person will do this.

I guess I have to start. Here goes:

Riddle 1
Chess Horses
The picture shows 2 white and 2 black horses placed in one section of the board. How we can exchange the positions of the white with the black horses?

Clarifications:

1.) Horses are allowed to move only within the block illustrated in figure.
2.) The movement of each horse must be the same as it does in chess, ie shape "Γ"
3.) A horse can overleap (jump above) other horses, but can not go to a square occupied by another horse.
4.) Give your movements using the numbers shown in each square.

Figure:



Long update: Use spoilers in your answers.

Good luck!

[Bridge]

Black to move? Also what do you mean "overcome"? As in they are allowed to take? Then you can't switch the positions.

EDIT: Never mind, I missed "cannot go to a square occupied by another horse".

[BAndrew]

Black to move? Also what do you mean "overcome"? As in they are allowed to take? Then you can't switch the positions.

EDIT: Never mind, I missed "cannot go to a square occupied by another horse".

You can move any of the horses you like and as many times as you want (for example you can move the (7) white piece 3 times in a row).

By overcome I mean, well it can "jump" other horses just like chess, but there can't be two horses at the same place. Generally just follow the chess rules.

Well fail "overcome" is not a word that fits there. Thanks, I'll get that fixed.

[Bridge]

Spoiler below!

1. Move the black knight on 1 to square 3.
2. Move the white knight on 7 to square 9.
3. Move the white knight on 5 to square 10.
4. Move the black knight on 6 to square 5.
5. Move the black and white knights on 3 and 9 to squares 2 and 8.

Can't get any farther at the moment. This is a really tough puzzle and I don't really want to waste my evening on it.

[BAndrew]

1. Move the black knight on 1 to square 3.
2. Move the white knight on 7 to square 9.
3. Move the white knight on 5 to square 10.
4. Move the black knight on 6 to square 5.
5. Move the black and white knights on 3 and 9 to squares 2 and 8.

Can't get any farther at the moment. This is a really tough puzzle and I don't really want to waste my evening on it.

Wait Wait Wait. Very good try, but the horses on chess don't move like this.

It is a shape "Γ" (move 2 blocks at one direction and then turn left or right and move 1 block).

"The horse moves to the nearest square not on the same rank, file, or diagonal. In other words, the horse moves two squares horizontally then one square vertically, or one square horizontally then two squares vertically. Its move is not blocked by other pieces: it jumps to the new location."

These are the possible moves the horse can make on chess:



A valid move is for example
1.)black 1-> 4
2.)white 7->1 etc.

You moved by 1 block in one direction and then 1 block left/right. This is wrong.

[Bridge]

1. Move the black knight on 1 to square 3.
2. Move the white knight on 7 to square 9.
3. Move the white knight on 5 to square 10.
4. Move the black knight on 6 to square 5.
5. Move the black and white knights on 3 and 9 to squares 2 and 8.

Can't get any farther at the moment. This is a really tough puzzle and I don't really want to waste my evening on it.

Wait Wait Wait. Very good try, but the horses on chess don't move like this.

It is a shape "Γ" (move 2 blocks at one direction and then turn left or right and move 1 block).

"The horse moves to the nearest square not on the same rank, file, or diagonal. In other words, the horse moves two squares horizontally then one square vertically, or one square horizontally then two squares vertically. Its move is not blocked by other pieces: it jumps to the new location."



A valid move is for example
1.)black 1-> 4
2.)white 7->1 etc.

You moved by 1 block in one direction and then 1 block left/right. This is wrong.

Actually to save myself a bunch of typing I simply designated the target square, because there is always only one way to get there.

So: Black knight on 1 to square 3 in reality means: Black knight to 4, 10, 2, 8, 9 and finally 3.

I play chess for hours every day so I have a pretty good idea of how knights move, but that post is excellent for the other people here who want a crack at the puzzle and don't understand your original instructions.

[BAndrew]

Actually to save myself a bunch of typing I simply designated the target square, because there is always only one way to get there.

So: Black knight on 1 to square 3 in reality means: Black knight to 4, 10, 2, 8, 9 and finally 3.

I play chess for hours every day so I have a pretty good idea of how knights move, but that post is excellent for the other people here who want a crack at the puzzle and don't understand your original instructions.

OK, this might get confusing so please type each move you make.
It's OK now because it's a start, but after 20 (for example [if neccessary]) moves it will certainly be a problem.

But anyway you are getting closer. Well done.

Yes, indeed. This post could be useful for somebody.

[Bridge]

Actually to save myself a bunch of typing I simply designated the target square, because there is always only one way to get there.

So: Black knight on 1 to square 3 in reality means: Black knight to 4, 10, 2, 8, 9 and finally 3.

I play chess for hours every day so I have a pretty good idea of how knights move, but that post is excellent for the other people here who want a crack at the puzzle and don't understand your original instructions.

OK, this might get confusing so please type each move you make.
It's OK now because it's a start, but after 20 (for example [if neccessary]) moves it will certainly be a problem.

Yes, indeed. It this post could be useful for somebody.

I don't think it's that much of a problem. I am making sure the target squares and all of the squares the knight must land on are unoccupied. If there is a knight there that needs to be moved, I will type the individual moves. But since we are talking about the same knight with basically a straight path I think it works well enough.

BTW, do you play any chess yourself? Maybe we could create a thread where the forum goers can play against eachother and post their games. Do you play any chess? Maybe we could create a thread where the forum goers can play against eachother and post their games.

[BAndrew]

I don't think it's that much of a problem. I am making sure the target squares and all of the squares the knight must land on are unoccupied. If there is a knight there that needs to be moved, I will type the individual moves. But since we are talking about the same knight with basically a straight path I think it works well enough.

BTW, do you play any chess yourself? Maybe we could create a thread where the forum goers can play against eachother and post their games. Do you play any chess? Maybe we could create a thread where the forum goers can play against eachother and post their games.

It won't be a problem for me, you and a few more, but for others it will. Anyway I don't have a personal problem with that.

Yes I do play chess myself and your idea is just awesome I'm in.

[Statyk]

Holy stromboli this is a tough one. BUT I'M SO CLOSE.