Light Bulb Moment
(Published on 2. November 2021, 22:31 by zegres)
In riddle Sudoku, you solve a riddle and use the answer to solve the sudoku.
- Lady Or The Tiger (CTC Solve, Bremster Solve)
- Light Bulb Moment (CTC Solve, Scott Strosahl Solve)
- 30 Zombies in 20 Minutes (CTC Solve, Bremster Solve)
- Time to Think Outside the Box (CTC Solve, Bremster Solve, Zetamath Solve from 1:30)
Light Bulb Moment
Riddle:
A long hallway has 43 light bulbs on the ceiling. Each light bulb has a pull cord that turns it on and off.
All the lightbulbs start turned off.
43 people go down this hallway.
The first person pulls every cord: 1,2,3,4... (now all bulbs are on)
The second person pulls every other cord: 2,4,6,8...
The third person pulls every third cord: 3,6,9,12...
And so on with the rest. Finally the 43rd person pulls cord 43.
Which bulbs are on after all the people have passed through?
Feel free to use the Sudoku Grid to work out the answer.
Sudoku:
Mark the final lit up bulbs in the Sudoku grid. (The hallway starts with Bulb 1 in R1C3)
Lit hallway cells are brighter (higher) than their hallway neighbors.
Hallway cells get darker (lower) as you get further away from a lit cell.
Between every two lit cells in the hallway there will be a darkest (lowest) cell. It can be anywhere between the two lit cells.
Arrows show the way through the hall. Digits allong an arrow sum to the circled digit.
Any Feedback is very welcome!
This Puzzle Was Featured on Cracking the Cryptic!
CTC Solve Video
Solve in F-Puzzles: (With Color) (No Color)
Solve in CTC: (With Color) (No Color)
Solution code: The positions of the lit bulbs (1-43) in order, Row 1 (18 digits no spaces)
Comments
on 1. March 2022, 21:51 by zegres
Added Links to New Riddles
on 1. March 2022, 13:42 by Krokant
It took me a moment to navigate around in the dark, but I feel enlightened now. Finding the darkest spots between the lit bulbs was a nice challenge. :)
Reply: Thanks for solving! You may want to try my new riddle sudoku (link at the top).
on 11. November 2021, 15:19 by uvo_mod
Labels angepasst.
on 3. November 2021, 05:21 by kolot
I liked the idea of combining riddles with sudoku. I think you should keep constructing such puzzles as long as they are solved. In particular, this one is very nicely executed with a pure grid, only bulbs and arrows showing the direction of the hallway. You may also think of a puzzle where the solution of the riddle is not used at the beginning but is used at the end to resolve a disambiguity.
Reply: good idea, I will try that if I come up with the right riddle. These are hard to set doing justice to both the riddle and the sudoku.
Reply: I can imagine how hard it can be to construct such a puzzle with a pure grid and no extra rule. This one is perfectly done.
Reply: Thanks a lot!
on 3. November 2021, 04:45 by Playmaker6174
As one of the first to test solving this one, it had some really interesting stuffs hidden in the path, the real challenge came from working on between the bulbs. Fun and enjoyable puzzle :)
on 3. November 2021, 02:50 by zegres
Added German Translation, Thanks Glum Hippo!
on 3. November 2021, 00:44 by zegres
Clarified solution code
on 3. November 2021, 00:35 by root_vegetable
For anyone confused about the solution code like I was, "Lit light bulb numbers" refers to the number *of* the bulb along the hallway, not the number *in* the bulb.
Reply: Thanks root_vegetable - I clarified.
on 2. November 2021, 22:59 by vidarino
Great and super-inventive puzzle! Loving these riddle sudokus!
