30 Zombies in 20 Minutes
(Published on 2. December 2021, 07:14 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)
30 Zombies in 20 Minutes
Riddle:
On a dark, moonless night, four friends are escaping a horde of 30 zombies.
They come to an old rickety bridge.
At most two can cross it at a time and they must use a flashlight to see.
They only have one flashlight, so someone must bring it back each time until everyone is across.
Shaun takes 1 minute to cross, Liz takes 3, Ed takes 7 and Dianne takes 9.
The zombies will get to the bridge in 20 minutes. How can everyone get across before they arrive?
Feel free to use the Sudoku Grid to work out the answer.
Sudoku:
Normal Sudoku rules apply.
Digits along an arrow sum to the circled digit.
Digits on indicated diagonals sum to the pointing value.
Rows 1,3,5,7,9 represent bridge crossing in order. The friends have to get from the left bank to the right.
Place them on the bridge (arrow) and the banks on either side. People are represented by their crossing time.
The sandwich clues to the right indicate the total time after each crossing. They equal the sum of digits between 1 and 9 in their row.
Any Feedback is very welcome!
CTC Featured This Puzzle! (Watch Here)
Solve in F-Puzzles: (With Color) (No Color)
Solve in CTC: (With Color) (No Color)
Solution code: Total Minutes For All Friends to Cross, Column 9 (11 digits)
Comments
on 12. July 2022, 13:01 by bbutrosghali
The sudoku part of this puzzle becomes significantly easier when you actually put in the correct sandwich sum in the final row, instead of mistakenly repeating the previous crossing's sum.
on 1. March 2022, 21:46 by zegres
Added Link to New Riddle
on 1. March 2022, 15:20 by Krokant
That was something else. The visualisation, the solving path, the idea itself - absolutely fantastic. Beautiful puzzle.
Reply: Glad you liked it! Thanks!
on 3. December 2021, 21:54 by zegres
Added German Translation (Thanks Glum Hippo!)
on 3. December 2021, 15:47 by Playmaker6174
Very fun and enjoyable puzzle, I like how tight the setting is and also how smooth the solve path afterwards is :)
on 3. December 2021, 07:52 by kolot
The grid looks like a perfect visualisation of the riddle. It should be very hard to come up with such a clean grid. Well done!
on 3. December 2021, 01:44 by Bremster
The interaction of riddle and puzzle is simply beautiful once again.
Thank you for these.
on 2. December 2021, 23:36 by Arlo Lipof
Wow! Superb combination of a classic riddle with the arrows and the sandwich clues!
on 2. December 2021, 09:27 by StefanSch
Fantastisch konstruiertes Rätsel! Mit nur zwei Hinweisen, die nicht durch die Hintergrundgeschichte festgelegt sind, ein eindeutiges Rätsel zu konstruieren, das ist schon eine Leistung. Respekt!
Reply:
Danke Schoen!
on 2. December 2021, 08:47 by vidarino
Wow, this is an awesome puzzle! How you manage to integrate the riddle part with the sudoku part so smoothly is a mystery to me. Fantastic job!
Reply:
Thanks for your nice comment!
There is no mystery it was just a BUNCH of trial and error.
