Cut a circular pizza into 12 congruent slices, such that exactly half of them contain crust.
Remark: We say that a slice contains crust if it shares an arc with the boundary of the pizza (with non-zero measure).
First, cut the pizza into 6 congruent circular triangles, and then split each of them in half, as shown on the image below.
White to play. Is this game a win for White, Black, or a draw?
This game is a win for White.
1. c7 Rd6+
2. Kb5 Rd5+
3. Kb4 Rd4+
4. Kb3 Rd3+
5. Kc2! Rd4!
6. c8=R! Ra4
7. Kb3
Now Black will either lose the rook, or get mated in one. If White promoted a Queen instead of a Rook, then 6… Rc4+ would lead to 7. Qxc4, which is a stalemate.
What wears a crown but is no Prince,
Is good at standing but cannot sit,
Digs for years but leaves no pit,
And wears its jewels inside of it?
The answer is TREE.
If you turn the handle of the top left gear clockwise, will the box in the bottom right open or close?
The box will open.
Insert the missing parentheses into each equation to make it true.
The solutions are:
“Intermediate Algebra for College Students” by Karl. J. Smith and Patrick J. Boyle
Reach the Goal by following the cats, alternating between cats facing forwards and cats facing backwards. The cats in your path must be connected or overlapping.
The path is outlined via the green cats below.
The main challenge of a Sunome puzzle is drawing a maze. Numbers surrounding the outside of the maze border give an indication of how the maze is to be constructed. To solve the puzzle you must draw all the walls where they belong and then draw a path from the Start square to the End square.
The walls of the maze are to be drawn on the dotted lines inside the border. A single wall exists either between 2 nodes or a node and the border. The numbers on the top and left of the border tell you how many walls exist on the corresponding lines inside the grid. The numbers on the right and bottom of the border tell you how many walls exist in the corresponding rows and columns. In addition, the following must be true:
Examine the first example, then solve the other three puzzles.
The solutions are shown below.
One day, the police finds a dead man inside a hut, with a bullet in his head. In his left hand, the man is holding a gun. In his right hand, he has a recording. When the recording is played, the police hears the man talking about how horrible his life has been and how he wanted it to end. The recording ends with a gunshot. The police are about to call it a suicide until a detective points out an important clue. What is it?
If the person shot himself and died, he wouldn’t have been able to stop the device from recording further.
The Cipher Solver Series is a collection of cipher puzzle books, written by D. H. Bernhardt. Each of the books teaches about various cipher techniques and then provides examples that help the reader master them. So far, there are 3 volumes released, and a fourth one is on its way.
Each book in the series starts with a short history on ciphers. Then, it provides 2 chapters on how to encode and decode specific ciphers, followed by 2 chapters with puzzle-examples. Finally, the books end with hints and solutions.
Volume 1 and 2 focus on the so-called Route and Rail ciphers, while volume 3 introduces us to the Pen and Polybius ciphers. The former are examples of transposition ciphers, those are ciphers in which the symbols are preserved, but their order is scrambled. The latter are examples of substitution ciphers, those are ciphers in which the original symbols are replaced with new ones.
The following example of a Rail cipher is taken out of the first book in the series. Let’s say the task is to encode the phrase “Beware of the attack from the North”. To do that, we create a rectangular grid and starting from the top left corner, we enter the letters of the phrase in a zigzag manner. We add some “X” letters at the end as padding, if necessary. This results in a route-like structure inside the grid, consisting of alternating diagonal rails.
Then, if we read the letters line by line, top to bottom, we get the encryption:
BOCT TXEE FAKM HRHX XWRA TFOE OXXA TRNX
To decrypt an encoded phrase, we just need to determine the dimensions of the grid and the size of the rails of the route. You can practice your route ciphering skills with the following puzzle from the book:
The transposition ciphers are fun but quite easy to solve, especially the Route ciphers. They all have been chosen with identical grid widths, so the only unknowns there are the route rails sizes. I recommend getting just one of the first two volumes, since the novelty in the second one lies mostly in the introductory chapter.
The two substitution ciphers are harder to solve and require more careful analysis. However, it is worth noting that the decoding procedure works identically for both of them, even though the ciphers use different encryption symbols.
Despite the remarks above, I think the books are educational, well-structured, and would be engaging to new cipher enthusiasts. I hope once the author completes his series, he considers combining the content in one larger edition divided into sections based on cipher type, such as transposition and substitution.
Please confirm you want to block this member.
You will no longer be able to:
Please note: This action will also remove this member from your connections and send a report to the site admin. Please allow a few minutes for this process to complete.
