Riddle: You've taken a job as a researcher in a remote and mysterious laboratory high in the Swiss Alps. Late one night, while you're working in the lab, you hear a loud crash just before the lab assistant bursts through the door, fleeing from the outstretched arms of a reanimated corpse. You and the lab assistant managed to get out into the hallway and bar the door shut behind you. Rounding a corner, you bump into the janitor and the old professor who oversees the lab work. They tell you that you must escape through an emergency exit at the back of the building that hasn't been used in years, as the front entrance has been overrun with zombies. You grab a flashlight and flee with your three companions out the rear emergency exit, into the darkness and down a hill before you arrive at a dilapidated rope bridge with fraying ropes and missing foot-boards. The bridge spans a wide gorge, and a fall means certain death, but it's your only method of escape. You hear the zombies crash through the emergency exit of the lab, and the professor quickly estimates that they will arrive at the foot of the bridge, where you are standing, in 17 minutes. Because the bridge is so worn and weathered, only two people can cross at once. Because it is pitch dark out with no moon to light your way, one person must come back across the bridge with the flashlight after they have crossed to allow anyone else to cross. And because the bridge is so rickety, you need to get everyone all the way across before the zombies arrive. (They'll run out onto the bridge and collapse it, so even if you're most of the way across when they reach the foot of the bridge, you'll die.) You are a spry young researcher, and it only takes you 1 minute to dash across the bridge. The lab assistant is a bit slower, and it takes her 2 minutes to cross the bridge. The janitor managed to twist his ankle coming down the hill, so it will take him 5 minutes to cross. And the professor is an hunched old man with arthritis-it takes him a full 10 minutes to cross the bridge. How do you get everyone across the bridge to safety in 17 minutes or less? Also, there are no tricks here. you cant swing across, use the bridge as a weapon or befriend the zombies!
Answer: At first, it seems like no matter what you do; you are just a minute or 2 short on time. But, there is a way. The key is to minimize the time wasted by the 2 slowest people. And since you will need to make some return trips with the lantern, you need to have the fastest 2 people available to do so. So, you and the lab assistant dash across first. This takes you 2 mins to do, since you need to match her pace. After, you should go back. 3 mins have passed. So far, so good. Next up, have the janitor and professor go next. This'll take 10 mins since the janitor needs to slow down for the old professor, who keeps muttering that he probably shouldn't have given the zombies night vision. After 10 mins have passed, the pair across the bridge. However, you are still on the wrong side of the bridge. But remember, the lab assistant has been waiting for you. So,with only 4 mins left; she grabs the lantern from the janitor and runs back across to you. Now, as you two make it across the bridge, you cut the ropes and collapse the bridge behind you, just in the nick of time. Maybe next time, you should stick to the library!
The bridge problem Riddle Meme with riddle and answer link.
