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Can you solve the bridge riddle? – Alex Gendler

Can you solve the bridge riddle? – Alex Gendler


Taking that internship
in a remote mountain lab might not have been the best idea. Pulling that lever with the skull symbol
just to see what it did probably wasn’t so smart, either, but now is not the time for regrets because you need to get away
from these mutant zombies fast. With you are the janitor,
the lab assistant, and the old professor. You’ve gotten a headstart,
but there’s only one way to safety: across an old rope bridge
spanning a massive gorge. You can dash across in a minute, while the lab assistant takes two minutes. The janitor is a bit slower
and needs five minutes, and the professor takes
a whole ten minutes, holding onto the ropes
every step of the way. By the professor’s calculations, the zombies will catch up to you
in just over 17 minutes, so you only have that much time
to get everyone across and cut the ropes. Unfortunately, the bridge can only hold
two people at a time. To make matters worse, it’s so dark out that you can barely see, and the old lantern you grabbed on
your way only illuminates a tiny area. Can you figure out a way
to have everyone escape in time? Remember: no more than two people
can cross the bridge together, anyone crossing must either
hold the lantern or stay right next to it, and any of you can safely wait in the dark
on either side of the gorge. Most importantly, everyone must be
safely across before the zombies arrive. Otherwise, the first zombie could step on
the bridge while people are still on it. Finally, there are no tricks to use here. You can’t swing across, use the bridge as a raft, or befriend the zombies. Pause the video now
if you want to figure it out for yourself! Answer in: 3 Answer in: 2 Answer in: 1 At first it might seem
like no matter what you do, you’re just a minute or two short of time,
but there is a way. The key is to minimize the time wasted
by the two slowest people by having them cross together. And because you’ll need to make
a couple of return trips with the lantern, you’ll want to have the fastest people
available to do so. So, you and the lab assistant quickly
run across with the lantern, though you have to slow down
a bit to match her pace. After two minutes, both of you are across, and you, as the quickest,
run back with the lantern. Only three minutes have passed. So far, so good. Now comes the hard part. The professor and the janitor take
the lantern and cross together. This takes them ten minutes since the janitor has to slow down
for the old professor who keeps muttering that he probably shouldn’t
have given the zombies night vision. By the time they’re across,
there are only four minutes left, and you’re still stuck
on the wrong side of the bridge. But remember, the lab assistant
has been waiting on the other side, and she’s the second fastest of the group. So she grabs the lantern
from the professor and runs back across to you. Now with only two minutes left,
the two of you make the final crossing. As you step on the far side of the gorge, you cut the ropes
and collapse the bridge behind you, just in the nick of time. Maybe next summer,
you’ll just stick to the library.

Comments (100)

  1. zombies had night vision but they fell down the bridge while not being on it?

  2. How did the prisoner escape the jail, having just a saw and a table in his cell ? Answer, he used the saw to cut the table into halves, and then since two halves make a whole, he just climbed out of the hole….. Of course, he was not quite literate . In the next cell was a Lawyer, who was arrested and being held for making a bribe to a judge. So within a week, he got notice from New York, that as an Attorney, he was disbarred. So he climbed out the window. ….

  3. They didn't tell you it was not an ordinary lantern. It was the Green Lantern..

  4. Just carry an old man on your back

  5. Ted ed:Can you solve…
    Me:No I can't

  6. I solved it but the most thing I liked was background music .where did you get it?

  7. he didn't say we can use guns,so that's my solution

  8. My class did this today and my Group was the closest one to get it ???

  9. Doing one riddle every morning, gives a great brain energy boost for the day

  10. instructions unclear; BUrIdE AlL My aSSiSTaNts ANd BrOUghT HOmE ThE bRIdGe

  11. She grabs the lantern from the janitor. not from the professor

  12. Bruh this is super easy I did it without looking at the answer…

  13. If there is 2 minutes left and she takes 3 minutes to cross back. It doesn’t add up

  14. 2:58 really ? Now you think of that

  15. Or you could carry one slow person and the other fast person carries the slow person.

  16. Why don’t use the scissors to kill the zombies you dident say that

  17. Solution: Just don’t take that internship

  18. Just put it on peaceful mode

  19. You Could Kill The Zombies By Lava Or Knifes

  20. I literally said the exact same thing to solve the riddle.

  21. I don't think the problem is that the zombies are stepping on the bridge and causing it to fall, i think it's that they are going to EAT you.

  22. Looks like the professors getting sacrificed

  23. There were more than 2 zombies so the bridge will collapse itself without cutting after u pass

  24. Or just use the scissors to slice the zombies head off

  25. If the zombies are Sooooo slow then why can't they close the skull lever before zombies get out like …. What

  26. if you let the two slowest cross first with the lantern and wait 2 minutes more just in case they took longer than expected, you and the assistant would still have 5 minutes to cross, which would still be plenty of time even without a lantern.

  27. This my first TED ED riddle I've solved before the answer was revealed. ….I'm so happy

  28. Why would janitor will be slow? can it takes 3 mij

  29. what the conversation between everyone would be like:
    me: ooh a switch
    press

    BRAIIINNNSSSSS…….

    Lab assistant: YOUVE DOOMED US ALL AAAAAAA

    Me: LISTEN I WAS GIFTED CURIOSITY
    everyone gets out
    Professor: we only have just over 17 minutes before we all die!
    janitor: all i see is a bridge

    lab assistant: well i do have this lantern!

    awkard moment of silence

    me: thats a terrible source of light….

    janitor: ENOUGH TALKING MORE PLANNING!

    me and lab assistant run across with lantern

    i run back with lantern

    me: TAKE THE LANTERN PROFESSOR

    I give lantern to professor

    janitor and professor walk across the bridge with lantern

    me: well im gonna die.

    lab assistant: takes the lantern from the professor I HAS A JOB TO DO

    lab assistant gets to me and we run across the bridge with lantern
    janitor: gives me a random pair of scissors CUT THA ROPES!

    cuts the ropes and everyone lives

    ____________________________
    your welcome,

  30. i dont have any proplem with slove this but i cant remember the numpers i should have a pen and peaper its well take a long time ?
    (Sry to bad english)

  31. Why don't you do a piggyback ride with the assistant come back then carry the janitor then come back again then get the professor thats 6 minutes

  32. Why can't you carry the professor? ?

  33. wait don't y'all have phones? just use the damn flashlight

  34. This was the video I found the channel by and this riddle is the absolute GOAT! I love it! It’s terrifying, which I hate, but still…!

  35. This gave me nightmares when I was little ?

  36. I rather take the lamp and go to the end of the bridge and just cut the bridge

  37. "Befriend the zombies"

  38. Who else did this in math class

    ⬇️

  39. But what about the 20 minutes it takes to figure out who goes when

  40. It's impossible for it to only hold two people. They would have to all weigh at least slightly different amounts

  41. Also zombies are easy to defeat, their bodies are rotting so it take would take at least half an hour. Wait, how long is the path to the bridge????

  42. jokes on you i jump off the mountain

  43. If u have scissors kill the zombies with them

  44. 3:28 lol when the zombies fall i laugh

  45. i'm a fan of the Chinese IQ test of the biasly abusive parents traveling with the police escorted violent criminal.
    https://www.youtube.com/watch?v=eDuvFO9aihw

  46. I've seen this before

  47. I think the time used to think how to solve the riddle probably got them eaten by the zombies

  48. i run in 1 minute and leve otheres to die giving them 17 minutes to find wepons in this way i am not kiling them directly

  49. I did the riddle in school and none of us got it right..

  50. "befriend the zombies"

  51. Easy we had this in school

  52. Why couldn’t the 2 fastest go without the lamp and the profesor and janitor just count 2 minutes and then go with the lamp and it only takes 13 minutes? There are ropes to help cross the bridge.

  53. I remember watching this all the time and now I’m obsessed

  54. I REALLY like this one!

  55. How about just crossing the bridge in the dark?

  56. What’s that music called?

  57. Make a mario video.

  58. Lol. We can swing the rope like Moana and Maui

  59. Teded: “Can you solve the-“

    Me, without missing a beat: no

  60. There is a faster way!
    Janitor and Professor go together equaling 10 minutes
    You run across and grab the lantern adding 1 more minute
    You run back across the bridge to get the lab assistant adding 1 more minute
    You and the lab assistant run to the other side together, adding 2 more minutes

    this is a total of 14 minutes

  61. Actually, if you know the exact amount of time it takes for each person to cross, once that amount of time is up automatically send another second person to cross the bridge. For instance, send the assistant and the professor, that’s two and ten minutes. After counting two minutes and knowing she is no longer on the bridge, then start crossing the bridge yourself. Another minute and now you are on the other side with her and the professor is still only three minutes into crossing, then the janitor can go. He crosses in five, the professor has two more minutes to go and boom problem solved. This is of course throwing out the lantern problem, just give it to one person and hold onto the ropes for directions lol.

    And it’s all under ten minutes since everyone got to go during the professor’s ten minutes.

  62. Can you kill them all?

  63. Did anyone else do this in science class? Or is it just us
    Just us okay

  64. I solved this 4 years ago

  65. Or maybe next time you don’t press a lever WITH A SKULL ON IT

  66. Couldnt i just carry the old man across

  67. Why not let the slow ones cross first – 10mins.. then I'll go and come back with lantern – 2 mins and then me and the lab assistant go- 2 mins.. done in 14?

  68. U do not need lantern

  69. In this order:
    2min + 1min – 2min
    2min goes back alone
    5min+10min-10min
    1min goes back alone
    1min+2min-2min
    Total=17min, you can now cut the bridge

  70. It can be done in 14 minutes. The old couple go first (10 mins). The fast runner runs across and back to fetch the lantern (2 x 1 mins) and the final two cross (2 mins)

  71. What if Thanos snapped his fingers and half of the people and zombies disappeared

  72. It's simple, let two people walk across with the lamp and immediately after, the others walk across without the lamp.

  73. I just love how they put intense music while explaining that theirs no tricks XD XD

  74. this is a bad bideo

  75. I almost got the right answer but the final answer is wrong

  76. Me: sorry, Old professor….ya shoulnda made the damn zombies in the first place, BYEEE!

  77. Plot twist, I wouldn’t of gone on that trip

  78. The old man is getting thorn off

  79. since the zombies are in a group, wouldn’t they all fall since the bridge can only hold 2 people at a time?

  80. Here's an idea – just pull and Indiana Jones by having the old professor cross, and then everyone holds on to the boards while you cut the line, swing to the cliff and use the bridge as a ladder

  81. You don’t even need to cut the bridge, as the zombies would collapse it…

  82. If this is reality, you would have been eaten by the zombies after you have thought of the answers.

  83. Carry the old professer

  84. Just pass through the bridge first with the young girl and without the lantern. You two are young and your eyes are still bright enough to see well in the dark. The 2 oldies can pass through together fine after that, with the lantern shining the way.

  85. Why not just have the fastest person run the lantern back each time.
    Ex: Professor (10 min) and you (1) cross
    You run back (+1 min)
    You take the janitor (+3 min)
    You run back (+1 min)
    You take the lab assistant (+2 min)
    It's the same. 17 minutes.

  86. The old professor was gonna die soon anyways. My solution: leave him behind.

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    Watch Now >> https://www.youtube.com/watch?v=RKBIoI3Ec3o

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  88. 0:52 the professor falls and everyone be like ?

  89. This video gave a cinematic goosebumps ??

  90. This is like the third variant I've seen on this riddle

  91. , boys don't do it.

  92. The music is COOL AF ! I would just listen to music and dance off ! Let others solve the riddle ??

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