Sunday Puzzle-22 |
| Written by Administrator | ||||
| Sunday, 30 September 2012 | ||||
 Puzzle courtesy of Barry R. Clarke, columnist for The Daily Telegraph and international puzzle expert A Pressing Problem  The Department of Silly Ideas has 16 push buttons on the front door arranged in a 4×4 square as shown. Each button is lit in one of the four colours in the rotating sequence: blue, red, yellow, green. When a button is pressed, its colour moves one forward in the sequence (e.g. pushing red makes it yellow, pushing green makes it blue etc.). In addition, three pairs of buttons each have an internal relationship where one button controls the colour of the other one but not vice versa. When the controlling button of the pair is pushed, its colour moves one forward while the controlled button colour moves one backwards. In the panel shown above, B1 controls C3, A3 controls D1 and D2 controls B4. So, for example, pressing A3 sends A3 from blue to red and D1 from green to yellow. However, pressing D1 just sends D1 from green to blue. Now entry into the department is gained by producing the same colour for all the buttons. What is the smallest number of button pushes required to gain entry? Related reading: Sunday Puzzle-21 Sunday Puzzle-20 Sunday Puzzle-19 Sunday Puzzle-18 Sunday Puzzle-17 Sunday Puzzle-16 Sunday Puzzle-15 Sunday Puzzle-14 Sunday Puzzle-13 Sunday Puzzle-12 Sunday Puzzle-11 Sunday Puzzle-10 Sunday Puzzle-9 Sunday Puzzle-8 Sunday Puzzle-7 Sunday Puzzle-6 Sunday Puzzle-5 Sunday Puzzle-4 Sunday Puzzle-3 Sunday Puzzle-2 Sunday Puzzle 
Write Comment |
||||
| Last Updated ( Sunday, 30 September 2012 ) | ||||
| < Prev | Next > |
|---|