Jolene, Charlie and Natalie were classmates. One of them cleaned up the classroom one day while there was nobody around. Below are their replies when the teacher questioned about who cleaned up the classroom.

Jolene: Charlie cleaned the classroom.
Charlie: I did not do it!
Natalie: Neither did I!

If one of them was telling the truth, who cleaned up the classroom?

There is a house. One enters it blind and leaves it seeing. What is it?

4 criminals are caught and are to be punished. The judge allows them to be freed if they can solve a puzzle. If they do not, they will be hung. They agreed.

The 4 criminals are lined up on some steps (shown in picture). They are all facing in the same direction. A wall separates the fourth man from the other three.

So to summarise :
Man 1 can see Man 2 and Man 3.
Man 2 can see Man 3.
Man 3 can see none of the others.
Man 4 can see none of the others.

The criminals are wearing hats. They are told that there are two white hats and two black hats. The men initially don’t know what colour hat they are wearing. They are told to shout out the colour of the hat that they are wearing as soon as they know for certain what colour it is.

They are not allowed to turn round or move. They are not allowed to talk to each other. They are not allowed to take their hats off.

Who is the first person to shout out and why?

Albert and Bernard became friends with Cheryl, and they want to know when her birthday is. Cheryl gives them a list of 10 possible dates.

```May 15      May 16      May 19
June 17     June 18
July 14     July 16
Aug 14      Aug 15      Aug 17
```

Cheryl then tells Albert and Bernard separately the month and the day of her birthday respectively.

Albert: I don’t know when Cheryl’s birthday is, but I know that Bernard does not know too.
Bernard: At first I don’t know when Cheryl’s birthday is, but I know now.
Albert: Then I also know when Cheryl’s birthday is.

When is Cheryl’s birthday?