Solution to Sudoku no 402

Sudoku no 402 (Extreme)

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Solution to Sudoku no 401

Sudoku no 401 (Extreme)

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Solution to Sudoku no 400

Sudoku no 400 (Easy)

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Solution to Sudoku no 399

Sudoku no 399 (Tough)

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Chess Solution no 1

40. ...  Bb4!

At which point white resigned because of:

41. Qxd8  Qxd8

 

This is apparently the least worst option for white.

There are other possibilities for white but analysis says they are even worse e.g.

41. Qb6   Rxd5

or

41. Qxa6  Rxd5

etc.

Other good moves for black would have been:

40. ...  Bf7

or

40. ...  Qd6

However, neither of these moves was actually played and they may not have resulted in resignation. Analysis says they are not quite as strong as the move which black chose.

Chess Puzzle no 1

This position is from Baron (2508) v. Smirin (2596), Israel, 2023. How did black (to play) finish the game?

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Solution to Killer Sudoku no 1

Killer Sudoku no 1

Unless stated otherwise:

I create the solutions for my killer sudoku puzzles using the C program which produces my standard 9x9 sudoku puzzles. I then create the puzzles by trial and error using Andrew Stuart's Killer Sudoku Solver This is fairly labour intensive so each one takes an hour or so to make.  

Usual sudoku rules apply i.e. each row, column and 3x3 mini-grid must have all of the numbers 1 to 9 exactly once. The puzzle is also divided into smaller areas called cages, which are surrounded by dashed lines. Numbers are not repeated within a cage. The number in the top left hand corner of each cage shows the sum of the numbers in that cage:

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Solution to Sudoku no 398

Sudoku no 398 (Extreme)

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Solution to Sudoku no 397

Here is my original version of the solution:

...and here is another version sent to me by y2k on Twitter:

...and another sent to me by Andrew on Twitter:

Sudoku no 397 (Diabolical)

According to SudokuWiki this diabolical sudoku puzzle has a grade of Very Hard / 742.

If you manage to complete it, please add a comment below saying how long it took you. If you also include your email address or Facebook name I will send you a similar puzzle which nobody else has ever seen.

I use the number of comments received to gauge the popularity of each puzzle type. This helps me to decide what to post in future.

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Solution to Sudoku no 396

Sudoku no 396 (Diabolical)

When you have solved this sudoku, please add a comment below saying how long it took you. You will need a Google account to do this.

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Solution to Sudoku no 395

Sudoku no 395 (Easy)

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Solution to Sudoku no 394

Sudoku no 394 (Diabolical)

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Solution to Sudoku no 393

Sudoku no 393 (Diabolical)

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Solution to Sudoku no 392

Sudoku no 392 (Diabolical)

If you have a Google account and were able to solve this, please comment below saying how long it took you.

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Solution to Puzzle no 391

Here is my original version of the solution:

...and here is another version, which Tina Park sent to me on Twitter:

Sudoku no 391 (Tough)

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Solution to Sudoku no 390

Sudoku no 390 (Easy)

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