Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

John speaks the truth only once a day in a week. Below are a few hints for you:

First: Days are Sunday, Monday and so on.
Second: One day he says, "I lie on Monday and Tuesday".
Third: On the next day, he says, "Today is either Thursday, Saturday or Sunday".
Fourth: On the next day, he says, "I lie on Wednesday and Friday".

Can you identify the day on which he speaks the truth?

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

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

What can run but never walk, have a mouth that never speaks, have a head that never weeps, and have a bed but never sleeps?

Outside a tattoo artist's shop, there was a signboard which read 'I make tattoos on only them who do not tattoo themselves'.

Reading it what do you think, does the tattoo artist tattoo himself?

Do you know of a place where the wind blows south and then suddenly shifts direction towards the north?

Below, you can see some coding:
January = 1017
February = 628
March = 1335
April = 145
May = 1353
June = 1064
July = 1074
August = 186

Now deciphering the way it has been coded, can you find out how September will be coded?

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

Which of the below owl is odd one out?