Here's the thing-they will think there is a trick. They will ask the following questions:
They will make all kinds of attempts to get around the actual solution. They will cut the paper in half and have you "walk through" it. They will cut out an arch and ask you to "walk through" it. They will be very creative and some will be determined. There will always be one or two students who claim, "Oh, I've done this before. I know what to do." And they are rarely the ones who know what to do.
This IS possible and the lesson it teaches is the foundation of a classroom who embraces a challenge. A class full of students who understands that they are learning when they are challenged.
It is ok to not know.
When you don't know, try. When you fail, figure out why.
In every attempt, you did something right and you learned from that.
When you struggle, look around and seek others who can help you.
Your classmates are not cheating by looking for inspiration. You are inspiring them by trying something new.
When someone gets it, share how you accomplished it. Become a leader and teacher to others. It is more important to help others learn than to keep the knowledge to yourself.
You might not have the answer, but you will if you keep working.
Things are much easier when you know how to do them.