Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

When Jack was six years old he hammered a nail into his favourite tree to mark his height. Ten years later at age sixteen, Jack returned to see how much higher the nail was. If the tree grew by five centimetres each year, how much higher would the nail be?

A sea diver is a real show-off. He showed everyone that he can hold his breath underwater for 15 minutes.

I went to the diver and told him that I can be underwater for double the time i.e 30 minutes.
He responded that he will give me 100$ if I would be able to do it. I won 100$.

What did I do?

What is full of holes but still holds water?

In the figure, you can see nine stars. What you have to do is connect all of them by using just four line and without lifting your hand i.e. in a continuous flow.

Write the next letter in this sequence.
O, T, T, F, F, S, S, E, __
**Hint: It is a Number Series Puzzle

Can you write down eight eights so that they add up to one thousand?

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

How can a man go eight days without sleep?

How many triangles can you count in the figure given?