When can we add 2 to 11 and get 1 as the correct answer?

Find the missing number in the sequence below:

You have an empty wine bottle with a cork that has been secured at the top in a normal way. There is a metal ring inside the bottle that is suspended by a string.

How can you make the metal ring drop to the bottom if you are not allowed to touch anything - not the bottle, not the cork, not the thread and not the ring?

Find The Next Number in this series.
1, 2, 6, 42, 1806 ?

What breaks yet never falls, and what falls yet never breaks?

Sherlock Holmes was challenged to make a pre-drawn line smaller without erasing it. He did it in fractions of seconds. How?

What can go through glass without breaking it?

Can you find out which options fits best with the missing column?

A boy and a girl are sitting on the porch.
"I'm a boy," says the child with black hair.
"I'm a girl," says the child with red hair.
If at least one of them is lying, who is which?

Find the next number in the sequence

1, 2, 6, 21, 88, __?