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.

100 thoughts on “Can you solve the bridge riddle? – Alex Gendler

  1. Dont worry…imma PRAY for jesus,nd he's gon save me…………不不不不

  2. (You cant befriend the zombies)years of academy training wasted

  3. Just do 2 at a time thats quicker even without the lantern, they can hold on to the ropes.

  4. oh my god this was the same activity I did in the 5th grade (now I'm in the 2nd year of high school ), but it was with animals and was meant to escape the storm, even though it's the smartest in the classroom (without bragging I couldn't solve this puzzle, in fact no one in the classroom had succeeded.
    how nostalgic

  5. Oooooh i have an idea what if you send the old professor and yourself so when you get to the other side the professor is 1/10 of the way through and you send the girl and by the time she gets to the other side the professor is 3/10 of the way there so you send the janitor as soon as the janitor crosses the bridge the professor will have gotten 8/10 of the way there and two minutes later they all have crossed the bridge, and the zombies will arrive at the bridge in seven minutes leaving them seven minutes to cut the bridge ropes and leave. I'm only 12. Hope I get it right.


  6. How did the old profesor even bend it should take him enough time for the zombies to eat their brains

  7. Two slowest go together on THE other side of THE bridge RIP the two fastest….

  8. So I took 5 whole minutes to solve the problem, this means I actually only had 12 minutes to cross. Scarier!!!!

  9. I dont understand why do you need lantern to cross the bridge… theres only one direction to go?

  10. Get a potion for all / get a command block /effect @e [type=player] speed 50 255

  11. If the professor was smart enough to calculate the time needed for the.zombies to catch up to them, he could certainly solve this problem himself

  12. Real talk, can we get a download link of the music playing during the explanation?

  13. As soon as I heard that the professor takes 10 mins……


  14. Just have the slowest crossing at the same time and you dont have to have the lantern and after they are done, you cross

  15. But dont forget
    Then spent 2 minutes watching the solution to the problem
    So they died anyway

  16. u carry the professor in ur arms
    1 minute
    go back by yourself
    1 minute
    give lantern to other girl
    she carries janitor across
    2 minutes
    she runs back by herself
    2 minutes
    u carry her across
    1 minute
    7 minutes!
    10 minutes left to get away
    no need to cut the bridge
    the bridgell collapse with all the zombies on it

  17. Put the professor in my back holding the lantern and cross the bridge, return and make the stronger one of the two do the same. Then just wait the lab assist come back and we are set to go

  18. The solution is not the most optimal, you can carry on your back the old man, drag him in the floor or use the lantern to cross and use sound and light to give a signal for the second group to start crossing using only the ropes. neither of this solutions are tricks, are valid and quicker options within the parameters given at the start of the riddle,

  19. So what you are saying is that we need at LEAST 4 people to cut a single rope with SHEARS?

  20. Just kill the professor hes old so its not that bad

  21. This is the first riddle from this channel I was actually able to solve, and thats saying much

  22. Simple solution: Dont built a lab on top of a mountain with a nearby gorge that can only be accessed via bridge.

  23. There is a simple answer. As there is only one side direction the professor and the Janitor can cross with the lamp (10 minutes in total) and the the guy and the assistant can cross whitout the lamp (2 minutes). In total you spent 12 minutes and the professor and the Janitor aren't so tired to continue with the Journey as the rested 2 minutes waiting the two guy.

  24. Considering the professor and the lab assistant will probably go to prison for causing the zombie outbreak and possibly murder and attempted murder(me) when they return to civilization I would help the janitor across then take off, I can be an @$$hole to those that try to screw me

  25. But seriously the 2 fastest cross then wave the lantern signaling the other 2 to cross after that cutting the bridge is optional the weight of the zombies will collapse the bridge unless you are trying to preserve evidence of the professor's experiment

  26. Send the two slowest first, that would only take them 10 minutes, because you dont count for the 5 minute guy he can slow and walk with the slowest. Takes 10 minutes. You run across in 1 minute. Youre at 11 now. Run back with the lantern in one minute. Youre at 12. Then you and the lab assistant run across in 2…. 14 minutes

  27. i find a lot of coments about: u don`t have to cut the bridge it will colapse on zombieS
    zombieS so it can`t be 1 but can 2 (at least) so….. [*] [*] [*] [*]
    also we do`nt know crossing time of zombies they might go trought bridge in a fraction of a second and the gap betwen them is 1/2 bridge legnth (also we don`t know how big the bridge is it might be 1 cm long (fastes guy speed then is 1cm/s)

  28. What if…. What if… What uf the zombies stack up and made a zombie bridge?

  29. Run across the bridge, cut the rope and sacrifice the other three and be on your way safe and sound. After all it's a lab assistant, a janitor and an old professor who probably isn't going to live much longer anyway so it's not like you're sacrificing 3 people who will make a big difference in the world.

  30. What am I missing? Shouldnt the prof and janitor go together first (10 min). Then you run over and bring the lantern back (2 min). And return with assistant (2 min). Total 14 min.

  31. There is an alternative solution but it requires a lot of back and forth. For the following all characters must travel at their full speed, no slowing down for their partner. First, send the professor and janitor across, when the janitor reaches the other side he immediately returns. The professor is across and the other three are on the wrong side, 10 minutes have passed. Second, send the lab assistant across and run across the bridge yourself and immediately return. The professor and lab assistant are now safe and 12 minutes have passed. Finally, travel across with the janitor such that you both are save, 17 minutes have passed.

  32. I'd pick up those slow mfs and run them across one by one and have 12 minutes to spare

  33. It said in 17 mins the zombies have caught up with you. Not that they are in the begining of the bridge. So in 17 mins they are at the end of the bridge not the begining so the video lied

  34. Old guy and the janitor first then let myself die and let the professor girl leg it across

  35. You didn't account for taking mindless selfies and posting to FB. That's an easy 10-15 additional minutes.

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