People make me, save me, change me, raise me. What am I?

What is at the end of a rainbow?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

Why do you find that most of the buildings are deprived of the 13th floor?

What is the largest number you can write with just 3 digits?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

A 3 digit number is such that it's unit digit is equal to the product of the other two digits which are prime. Also, the difference between it's reverse and itself is 396.

What is the sum of the three digits?

It spends most of its day eating white, but when it’s quick enough, it gets to eat fruit and sometimes some blue things. It’s in a dark room, where the walls are blue, it runs from a ghost that roams the halls and haunts it all the time. What is it?

Two girls were born to the same mother, on the same day, at the same time, in the same month and year and yet they're not twins. How can this be ?

Sherlock Holmes was challenged to make a pre-drawn line smaller without erasing it. He did it in fractions of seconds. How?