A maths symbol is hidden in the below Bar Graph. Can you decipher it?

What number should come in place of the question mark below?

What does the following BrainBat signifies?

ABCDEFGHIJKLMNOPQRSTUVWYZ

QQQQQQQQQQQQQQQQQQQQQQQQQ.

What can you see in the middle of March and April that you can never see in any other month?

A couple went to a hill station to enjoy their vacation. They have 12 sons, and each has a wife who has 3 sons further.

How many people went to the hill station?

Can you find the missing piece of the Porsche?

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?

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?

Place a mathematical symbol between the numerals 5 and 9 in such a way that the resulting number is greater than 5 but smaller than 9.

I look at you, you look at me, I raise my right, you raise your left. What am I?