What four weights can be used to balance from 1 to 30 pounds?

Once upon a time, there was a castle on a square island. The entire island was surrounded by a 14m wide trench. The Romans had wanted to invade the castle and had brought a few wooden planks along with them to facilitate themselves in crossing the moat. The planks were however found to be only 13m long.

The Romans still managed to cross the trench. How did they do it?

A high school has a strange principal. On the first day, he has his students perform an odd opening day ceremony:

There are one thousand lockers and one thousand students in the school. The principal asks the first student to go to every locker and open it. Then he has the second student go to every second locker and close it. The third goes to every third locker and, if it is closed, he opens it, and if it is open, he closes it. The fourth student does this to every fourth locker, and so on. After the process is completed with the thousandth student, how many lockers are open?

What do you think with the below Picture ?

How can you leave a room with two legs and return with six legs?

Two Twins Jack and Jill were standing back to back and suddenly they started running in opposite direction for 4 kilometres and then turn to left and run for another 3 kilometres.

what is the distance between the Baggio twins when they stop ?

Replace the (?) with the correct mathematical signs to make the expression equal to 59.

18 ? 12 ? 4 ? 5 = 59

How much will a 38° angle measure when looked at under a microscope that magnifies ten times?

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

What is full of holes but still holds water?