# Come out alive from locked room [duplicate]

You are locked in a 50 x 50 x 50-foot room which sits on 100-foot stilts. There is an open window at the coner of the room, near the floor, with a strong hook cemented into the floor by the window. So if you had a 100-foot rope, you could tie one end to the hook, and climb down the rope to freedom. (The stilts are not accessible from the window. ) There are two 50-foot lengths of rope, each cemented into the ceiling, about 1 foot apart, near the center of the ceiling. You are a strong, agile rope climber, good at tying knots,and you have a sharp knife. You have no other tools (not even clothes). The rope is strong enough to hold your weight, but not if it is cut lengthwise. You can survive a fall of no more than 10 feet.

How do you get out alive?

This answer assumes whoever built this place is sane, which is a shaky assumption at best from the sound of it.

Climb one rope, cut the other down completely, letting it fall to the floor. Climb back down.

Take your 50-foot rope, tie it to the hook by the window. Climb out to the end, and start swinging back and forth in line with the nearest stilt. Once you can reach it, climb down and find some clothes.

When I said it assumes the builder is sane, I mean that the room is supported by at least one stilt, and that these stilts are positioned in some fashion that evenly distributes the weight of the room among them.

If this is the case, the furthest a stilt could be from a window at any corner's floor is about 35 feet away (a single stilt dead-center is 25*sqrt(2)). With a 50-foot(ish) rope, you'd only need to swing out to an angle of about 45 degrees from vertical, which should be easily managed. You'd end up about 35 feet down the stilt.

Of course, if the guy's crazy (very likely) and planted a single stilt on a corner opposite the window or something, you're probably better off using another method. Then again, it might be better to just jump out the window anyway, since he'll probably just capture you again and put you through some other bizarre trial.

• This is exactly what lateral thinking should be. A logical solution that follows everything in the problem, but without using loopholes that make it trivial. This may not be the answer that OP was looking for, but I don't see what people could possibly object to here. +1 to you. – mdc32 Dec 6 '14 at 3:05

You climb up one of the 50 foot lengths of rope. Then when you get within a couple feet of the ceiling, you do the following:

Hold the rope with your left hand and use your right hand to grab the other 50 foot length of rope. Put it in your left hand so that your left hand is holding both ropes. With your right hand, use the knife to cut each rope halfway through its thickness. So if each rope is 1-inch thick, you make a half-inch cut in each one. Even though each rope is partially cut, neither one should break since each one is only supporting half of your weight now. Then grab one rope with your right hand, so that each hand is holding a rope.

Now climb down to the floor and do the following:

Grab one rope and start climbing it a few feet. It will break since it is partially cut and cannot support your weight. Do the same with the other rope.

Now you have 2 ropes on the floor that are almost 50 feet long each. Tie the ropes together at the ends, so that you have one rope that is almost 100 feet long. Then tie one end to the hook. Toss the rope out the window, and the other end will be within a few feet of the ground. Climb down to safety. You are alive and on the ground!

• Pretty gutsy to cut half of each! Clever, too. – Michael Dec 6 '14 at 4:36

Climb the the top and cut one rope near the ceiling leaving enough to tie a loop hanging from the ceiling. Climb down and tie the long piece you cut off to the piece still hanging from the ceiling, so you have a length of rope almost 100 feet long, still attached to the ceiling. Take the loose end, climb to the top and thread it through the loop. Now cut the other rope from the ceiling and lower yourself to the ground. Since the rope is nearly 100 feet long and you will need to hold both ends of the rope threaded through the loop, you can lower yourself 50 feet. Then pull the rope out from the loop, tie it to the hook, and lower yourself down.

• This is the canonical answer. Well done. – Joe Z. Dec 7 '14 at 5:43