Why is it very easy to weigh a fish?

Can you find out the smallest number that can be conveyed as the sum of three squares in three unique ways?

John enters a small room. The Door Closes.
When the door opens, John is in a larger room.

Explain?

what does this below rebus represent identXQQQQQME

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

It has a long neck, A name of a bird, Feeds on cargo of ships, It's not alive,

What is it?

Begin with a word, five letters to my name,
Remove the first and last but I am the same
Take out my middle and still, I remain.
What word am I?

On a magical land of Mexico , all the animal in the land are rational.

There are 10 tigers and one goat.
Tiger can eat goat but since it's a magical land , the tiger who eats the goat , turns into goat and then can be eaten by the remaining tiger(s).

If we leave them for some time then how many goat and tiger will be there , when we come back ?

The day before yesterday I was 25 and the next year I will be 28. This is true only one day in a year. What day is my birthday?

Open a Laptop which is password protected. Hint for the password is given as below:

1 mobile 3 books 2 Boards 1 night 4 balls 2 lighters 1 ghost 1 hat 3 watches