Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

Christina, Allison and Lena are 3 daughters of John a well-known Mathematician, When I asked John the age of their daughters. He replied "The current age of her daughters is prime. Also, the difference between their ages is also prime."

How old are the daughters?

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.

What has to be broken before you can use it?

A very interesting trivia question for all.

Why do men's shirts have their buttons on the right side and women's have buttons on the left-hand side?

How many letters are in the alphabet?

How many words can a pen with half refill write?

Can you find the thief by just looking at the picture below?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?