I have no life, but I can die. What am I?

The more of this there is, the less you see. What is it?

I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

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 does below Rebus say?

XLR8

What does Alexander the Great and Winnie the Pooh have in common?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

I am a type of word that is spelt incorrectly or used differently, on purpose for humour. What am I?
Hint 1: You can find me in a joke.
Hint 2: I am a play on words.

I want to fill my bucket using both cold and hot water.
I have two taps for both cold and hot water. The hot water tap fills the bucket in exact 6 hours and the cold water tap fills the bucket in exact 4 hours.
I turn both of them simultaneously but I forgot to turn off another tap which removes the water out of the bucket. This tap can empty the bucket in 12 hours.

How Long will it take to fill the bucket?

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?