What is full of holes but still holds water?

When it's bad luck to meet a black cat?

Which alphabet letter is a question?

What runs around the whole yard without moving?

John speaks the truth only once a day in a week. Below are a few hints for you:

First: Days are Sunday, Monday and so on.
Second: One day he says, "I lie on Monday and Tuesday".
Third: On the next day, he says, "Today is either Thursday, Saturday or Sunday".
Fourth: On the next day, he says, "I lie on Wednesday and Friday".

Can you identify the day on which he speaks the truth?

How many Watermelons are there in the below picture?

An octopus has 8 legs. A hippogriff has 6 legs and 2 pairs of wings. A sphinx has 6 legs and one pair of wings. Now we have all 3 kinds and a total of 18 insects in a cage. We have a total of 118 legs and 20 pairs of wings. How many insects do we have of each kind?

What is the four-digit number in which the first digit is one-third the second, the third is the sum of the first two, and the last is three times the second?

When I asked a girl's name she told me her name is the date '07/09/2001'.

I thought for a few seconds and then I got her name. Do you?

What does the following represent?

N N N N N N N

A A A A A A A

C C C C C C C