A man who lives on the tenth floor takes the lift down to the first floor every morning and goes to work. In the evening, when he comes back; on a rainy day, or if there are other people in the lift, he goes to his floor directly. Otherwise, he goes to the seventh floor and walks up three flights of stairs to his apartment. Why? Answer

There are three switches downstairs. Each corresponds to one of the three light bulbs in the attic. You can turn the switches on and off and leave them in any position. How would you identify which switch corresponds to which light bulb, if you are only allowed one trip upstairs? Answer

One day a girl celebrated her birthday. Two days later, her older twin brother celebrated his. How is this possible? Answer

A three volume set of books stands on the bookshelf. Each cover is 1/4 of an inch thick and the pages of each book are 1 inch thick. A bookworm starts on page 1 of volume 1 and eats his way to the last page of volume 3. How far does he travel? Answer

A cube of cheese is divided into 27 subcubes. A mouse starts at one corner and eats each subcube, proceeding to the next that touched a face of the just-eaten subcube (i.e. subcubes must touch on faces). Can it finish in the middle? Answer

Which came first: the chicken or the egg? Answer

Move just two sticks to put the cherry in the wineglass. Answer

What’s the next letter in the sequence: P O I U Y T R E W ? Answer

What occurs twice in a lifetime, but once in a year, twice in a week but never in a day? Answer

A man has to get a fox, a chicken, and a sack of corn across a wide, deep river. He has a rowboat, and it can only carry him and one other thing. If the fox and the chicken are left together, the fox will eat the chicken. If the chicken and the corn are left together, the chicken will eat the corn. How does he do it? Answer

How many letters are there in the answer to this question? Answer

The number **8549176320** has no particularly interesting mathematical properties (that I know of), yet, it has a unique method of construction. What is it? Answer

How can you cut a circular birthday cake into 8 equal-sized pieces with only 3 cuts? Answer

What’s the next letter in the series: O T T F F S S E _ Answer

What is the minimum number of saw cuts you’d need to cut 27 cubelets from a large wooden cube, i.e. 3x3x3 like Rubik’s Cube? You may take any cut pieces and put them together any way you like for the next cut, which counts as one cut only. Give a simple reason for your answer… Answer

What do these words have in common? **ailed asset gem lien map nave nomad yak** Answer

John is standing behind Mary, and Mary is standing behind John. How is this possible? Answer

A man walks one mile due South, then one mile due East, and finally one mile due North, and ends up where he started. He’s not at the North Pole. Where is he? Answer