I am a type of room you cannot enter or leave. Raised from the ground below, I could be poisonous or a delicious treat. What am I?

I have a five and a three-gallon jar. Assuming there is an infinite supply of water, how can I measure one-gallon water?

Spot 5 differences in two Christmas tree below:

A man says, "Brothers and sisters, have I none, but that man's father is my father's son." Who is that man?

Can you spot the hidden girl in the picture below?

A boy collects white seashells from the sea and brings them home every night. When he has enough of them, he decides to sell them to a trader.

The trader is ready to buy the shells and he asks the boy about the quantity. At this, the boy starts calculating. He has a giant box that contains 3 mini boxes. Two of them have another mini box inside. If the giant box can hold 50 shells, how many brown shells can he sell to the trader?

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

It is always ahead of me yet I can never see it. What is it?

What brings you down but never up?

If Japan and Panama decided to merge into a single country, probably people will name it Japanama.

Can you think of two more such country's unions that could produce similar names like Japanama by overlapping their three letters?