# 53 bicycles: A lateral thinking puzzle **URL:** \ **Category:** Thread Games\ **Created:** [July 9, 2017, 7:51pm UTC](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868 "2017-07-09T19:51:32Z")\ **Posts on this page:** 20\ **Page:** 133
**Author:** ![MonkeyMensch](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@MonkeyMensch](https://boards.straightdope.com/u/MonkeyMensch)\ **Post date:** [March 1, 2018, 1:46am UTC](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868/2641 "2018-03-01T01:46:57Z")
Had the water been boiled recently? Had the water been used for fighting fires? ---
**Author:** ![Mahaloth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mahaloth/32/1079_2.png) [@Mahaloth](https://boards.straightdope.com/u/Mahaloth)\ **Post date:** [March 1, 2018, 2:05am UTC](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868/2642 "2018-03-01T02:05:29Z")
> [@IvoryTowerDenizen](#): > > Was the tank under pressure when he entered? No > [@MonkeyMensch](#): > > Had the water been boiled recently? > Had the water been used for fighting fires? No. I modified the original puzzle to be a little better, but I want to post it as I heard it in order to make sure everything is clear. I think you will find it is not that different. I just don’t want to have messed it up. As heard: A completely healthy worker in a factory was inspecting the inside of a tank that had only been used to hold fresh water. It was upright with the usual manhole entry in the top about 4 meters deep with a diameter of 2 meters. There was 15 cm water on the bottom. He wasn’t wearing any safety breathing gear because there hadn’t been anything poisonous in the tank. Shortly after entering the tank, he keeled over and died. Why? ---
**Author:** ![Walken\_After\_Midnight](https://avatars.discourse-cdn.com/v4/letter/w/b487fb/32.png) [@Walken\_After\_Midnight](https://boards.straightdope.com/u/Walken_After_Midnight)\ **Post date:** [March 1, 2018, 2:17am UTC](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868/2643 "2018-03-01T02:17:18Z")
- Was Gabe wearing any thing that acted as a barrier to the air in the vicinity (e.g. a respirator mask, hazmat or deep sea diver suit)? - Did the chemical reaction occur because of something to do with Gabe’s physical body (carbon-based humanoid life form)? - Did the chemical reaction occur because of something to do with what Gabe was wearing, equipped with, carrying etc? ---
**Author:** ![MonkeyMensch](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@MonkeyMensch](https://boards.straightdope.com/u/MonkeyMensch)\ **Post date:** [March 1, 2018, 2:46am UTC](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868/2644 "2018-03-01T02:46:02Z")
Is what the factory produces relevant to the solution? ---
**Author:** ![Mahaloth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mahaloth/32/1079_2.png) [@Mahaloth](https://boards.straightdope.com/u/Mahaloth)\ **Post date:** [March 1, 2018, 3:40am UTC](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868/2645 "2018-03-01T03:40:11Z")
> [@Walken\_After\_Midnight](#): > > - Was Gabe wearing any thing that acted as a barrier to the air in the vicinity (e.g. a respirator mask, hazmat or deep sea diver suit)? NO > > - Did the chemical reaction occur because of something to do with Gabe’s physical body (carbon-based humanoid life form)? NO > > - Did the chemical reaction occur because of something to do with what Gabe was wearing, equipped with, carrying etc? NO > [@MonkeyMensch](#): > > Is what the factory produces relevant to the solution? NO I am thinking it _is_ relevant that the lid/manhole-entry **was closed** by Gabe. It must have been, though I did not have that information in the puzzle as I read it. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 1, 2018, 3:42am UTC](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868/2646 "2018-03-01T03:42:17Z")
Was the water the result of something else in the tank combusting? ---
**Author:** ![j666](https://avatars.discourse-cdn.com/v4/letter/j/9de0a6/32.png) [@j666](https://boards.straightdope.com/u/j666)\ **Post date:** [March 1, 2018, 4:19am UTC](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868/2647 "2018-03-01T04:19:25Z")
Was water the only substance currently in the tank? Was the tank vertical? ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [March 1, 2018, 9:38am UTC](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868/2648 "2018-03-01T09:38:51Z")
> [@Mahaloth](#): > > I am thinking it _is_ relevant that the lid/manhole-entry **was closed** by Gabe. It must have been, though I did not have that information in the puzzle as I read it. So, did the lid form a seal causing Gabe to suffocate? Was Gabe carrying an oxygen-consuming device like a lantern? Which therefore consumed the oxygen causing Gabe to suffocate. ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [March 1, 2018, 10:32am UTC](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868/2649 "2018-03-01T10:32:02Z")
Did the tank fall over and get inverted so that the water formed a seal so Gabe suffocated? ---
**Author:** ![Mahaloth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mahaloth/32/1079_2.png) [@Mahaloth](https://boards.straightdope.com/u/Mahaloth)\ **Post date:** [March 1, 2018, 2:57pm UTC](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868/2650 "2018-03-01T14:57:51Z")
> [@Chronos](#): > > Was the water the result of something else in the tank combusting? No. > [@j666](#): > > Was water the only substance currently in the tank? YES > > Was the tank vertical? NO. > [@Quartz](#): > > So, did the lid form a seal causing Gabe to suffocate? **I think it must have sealed off the outside, but it wasn’t a vacuum.** > Was Gabe carrying an oxygen-consuming device like a lantern? NO > > Which therefore consumed the oxygen causing Gabe to suffocate. NO > [@Quartz](#): > > Did the tank fall over and get inverted so that the water formed a seal so Gabe suffocated? NO kk ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [March 1, 2018, 5:11pm UTC](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868/2651 "2018-03-01T17:11:47Z")
Hold it. In the puzzle you state that the tank was upright, but in your answer to j666 you say it wasn’t vertical. I’m confused. I’m guessing this is a clue. ---
**Author:** ![Mahaloth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mahaloth/32/1079_2.png) [@Mahaloth](https://boards.straightdope.com/u/Mahaloth)\ **Post date:** [March 1, 2018, 6:14pm UTC](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868/2652 "2018-03-01T18:14:32Z")
> [@Quartz](#): > > Hold it. In the puzzle you state that the tank was upright, but in your answer to j666 you say it wasn’t vertical. I’m confused. I’m guessing this is a clue. No, it isn’t. I don’t have a diagram or photo(this event is real, too). Maybe it was upright/vertical. I pictured it not being. I’m not trying to be confusing. I think it was tall and skinny, not flat and wide. ---
**Author:** ![Paintcharge](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/paintcharge/32/7946_2.png) [@Paintcharge](https://boards.straightdope.com/u/Paintcharge)\ **Post date:** [March 1, 2018, 6:52pm UTC](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868/2653 "2018-03-01T18:52:33Z")
Was there something living in the tank? Snake, spider etc? ---
**Author:** ![Folly](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/folly/32/3219_2.png) [@Folly](https://boards.straightdope.com/u/Folly)\ **Post date:** [March 1, 2018, 7:00pm UTC](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868/2654 "2018-03-01T19:00:04Z")
Did something happen to cause Gabe to want to inspect the tank? Was the water no longer fresh water in the tank? If yes to no longer fresh, is that relevant? Did we establish Gabe is human? and He refers to Gabe? ---
**Author:** ![Mahaloth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mahaloth/32/1079_2.png) [@Mahaloth](https://boards.straightdope.com/u/Mahaloth)\ **Post date:** [March 1, 2018, 8:26pm UTC](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868/2655 "2018-03-01T20:26:32Z")
> [@Paintcharge](#): > > Was there something living in the tank? Snake, spider etc? No. > [@Folly](#): > > Did something happen to cause Gabe to want to inspect the tank? No. > > Was the water no longer fresh water in the tank? If yes to no longer fresh, is that relevant? Probably not fresh. Irrelevant > > Did we establish Gabe is human? and He refers to Gabe? Yes and yes. ---
**Author:** ![Knowed\_Out](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/knowed_out/32/7380_2.png) [@Knowed\_Out](https://boards.straightdope.com/u/Knowed_Out)\ **Post date:** [March 2, 2018, 12:41am UTC](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868/2656 "2018-03-02T00:41:52Z")
Was there another element with the water prior to the tank being opened? ---
**Author:** ![Mahaloth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mahaloth/32/1079_2.png) [@Mahaloth](https://boards.straightdope.com/u/Mahaloth)\ **Post date:** [March 2, 2018, 12:44am UTC](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868/2657 "2018-03-02T00:44:38Z")
> [@Knowed\_Out](#): > > Was there another element with the water prior to the tank being opened? I’m not sure I get your question, but I think **NO**. It was a tank with water. Certainly the tank is made up of molecules made up of atoms. ---
**Author:** ![Walken\_After\_Midnight](https://avatars.discourse-cdn.com/v4/letter/w/b487fb/32.png) [@Walken\_After\_Midnight](https://boards.straightdope.com/u/Walken_After_Midnight)\ **Post date:** [March 2, 2018, 3:24am UTC](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868/2658 "2018-03-02T03:24:57Z")
- Was the tank airtight before Gabe arrived? - Did the chemical reaction occur before Gabe arrived? - Surely someone would notice if they couldn’t breathe and would try and rectify the situation - did Gabe notice that he couldn’t breathe, let’s say at least a few seconds before he died (which would presumably have given him enough time to leave the tank in normal circumstances)? - If so, was he unable to save himself for some reason? - If someone else was standing outside the tank when Gabe entered, would they also have died? ---
**Author:** ![Mahaloth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mahaloth/32/1079_2.png) [@Mahaloth](https://boards.straightdope.com/u/Mahaloth)\ **Post date:** [March 2, 2018, 3:47am UTC](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868/2659 "2018-03-02T03:47:25Z")
> [@Walken\_After\_Midnight](#): > > - Was the tank airtight before Gabe arrived? YES > > - Did the chemical reaction occur before Gabe arrived? YES > > - Surely someone would notice if they couldn’t breathe and would try and rectify the situation - did Gabe notice that he couldn’t breathe, let’s say at least a few seconds before he died (which would presumably have given him enough time to leave the tank in normal circumstances)? I don’t know. I guess not. > > - If so, was he unable to save himself for some reason? I guess not. > > - If someone else was standing outside the tank when Gabe entered, would they also have died? NO I’m starting to not be a fan of my own puzzle here. I think it might be an inadequate puzzle. Let me know if you guys want the solution. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 2, 2018, 4:14am UTC](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868/2660 "2018-03-02T04:14:36Z")
I don’t know how relevant it is to this puzzle, but you don’t actually notice a shortage of oxygen, just a surplus of carbon dioxide. This is one of the hazards of liquid nitrogen in an enclosed place: If the evaporating nitrogen displaces the oxygen, you can pass out and eventually die without ever noticing. [Previous page](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868.md?page=132) [Next page](https://boards.straightdope.com/t/53-bicycles-a-lateral-thinking-puzzle/790868.md?page=134)