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Showing posts from July, 2014

### 3D Tic Tac Toe Puzzle

Source: Shared by Alok Mittal (Cannan Partners)
Problem: A 3x3 tic tac toe has 8 "winning lines" (3 horizontal, 3 vertical and 2 diagonals). How many "winning lines" does the 3x3x3 3D tictactoe have? There is a brute force solution, and then there is the aha! solution.

Update (23 Oct 2014)
Solution: Posted in comments by Anti, Taz, Javier, Shubham Gupta, Leela. Detailed solution and much more advanced problems in the document http://library.msri.org/books/Book42/files/golomb.pdf

Source:http://nrich.maths.org/

Problem:

A mad robot sets off towards the North East on a journey from the point (0,0) in a coordinate system. It travels in stages by moving forward and then rotating on the spot. It follows these pseudo-code instructions:

SUB JOURNEY
DISTANCE = 1000
WHILE (DISTANCE > 0.001)
MOVE DISTANCE
STOP
ROTATE(90, DEGREES, CLOCKWISE)
DISTANCE = DISTANCE / 2
END WHILE
EXPLODE
END SUB

Where does the robot explode?

Update (23 Oct 2014):
Solution: Posted by me (Pratik Poddar) in comments!