The average age of 10 members of a committee is the same as it was 4 years ago, because an old member has been replaced by a young member. Find how much younger is the new member ?

Why is 6 afraid of 7?

Can you find the missing letter in the sequence?
S - T - I - L - ? - T - F - Y - C

Prove that twice of ten is the same as twice of eleven.

What time is it when an elephant sits on a fence?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

Find the next number in the series below

21 32 54 87 131 ?

There is a place where if I stand up straight, I will still be considered sideways.

In case you were starting to feel confident, this one was meant for third graders in Vietnam. The answer is 66, but we don't blame you for scratching your head about how they got there.

The product of three consecutive numbers is 7980.
Then the sum of these consecutive numbers would be?