They are the five precious gems of an everyday sort and all can be found on a Tennis Court. Who are they?

There is a basket full of hats. Three are white and two are black. Three men, Tom, Tim, and Jim, each take a hat out of the basket and put it on their heads without seeing the hat they selected or the hats the other men selected. The men arrange themselves so Tom can see Tim and Jim’s hats, Tim can see Jim’s hat, and Jim can’t see anyone’s hat. Tom is asked what color his hat is and he says he doesn’t know. Tim is asked the same question, and he also doesn’t know. Finally, Jim is asked the question, and he does know. What colour is his hat?

A man is found dead with a knife in his back When the investigation is done. A chair lays beside him and the forensic team finds moisture around the body.

If he committed suicide, how did he do it?

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.

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

2, 3, 5, 9, 17, _ What is the next number in the sequence?

A shepherd had 18 sheep, out of which, all but ten died.

Can you tell us how many sheep was he left with?

I am thinking of a five-digit number such that:
The first and last digits are the same, their submission is an even number and multiplication is an odd number and is equal to the fourth number. Subtract five from it and we obtain the second number. Then divide into exact halves and we get the 3rd number.

What number I am thinking of?

Below is the sum of symbols in each row and column in the figure. Analyzing the figure, can you find out the value of the symbols?

I travel all around the world but always stay in the corner. What am I?