In the image below, can you find the value of an angle(y)

In this image, you can see three almost identical Doraemon images. Can you spot the odd one out from them?

There is an English word that can be used up to four times in a row without modifying the spelling and form a valid grammatical sentence.

Do you know what word is that?

What is the coolest letter in the alphabet?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

Can you count the number of triangles in the given figure?

Replace the question mark with the correct number.

2 + 2= 4
3 + 3= 18
4 + 4= 48
5 + 5= ?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

One absent-minded ancient philosopher forgot to wind up his only clock in the house. He had no radio, TV, telephone, internet, or any other means for telling time. So he travelled on foot to his friend's place a few miles down the straight desert road. He stayed at his friend's house for the night and when he came back home, he knew how to set his clock. How did he know?

There was a strange boy who was born before his father. How can this be possible?