I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

What does below rebus means ?

A bag contains 64 balls of eight different colours. There are eight of each colour (including red). What is the least number you would have to pick, without looking, to be sure of selecting 3 red balls?

It's a protector.
It sits on a bridge.
One individual can see directly through it, while others wonder what it hides.

What is it?

What does the following BrainBat signifies?

ABCDEFGHIJKLMNOPQRSTUVWYZ

QQQQQQQQQQQQQQQQQQQQQQQQQ.

There once were seven dwarfs who were all brothers. They were all born two years apart. The youngest dwarf is seven years old. How old is his oldest brother?

This is a classy optical illusion puzzle. What more you can find except bricks in the image below?

When can we add 2 to 11 and get 1 as the correct answer?

There are are five things wrong with this sentence; only geniuses will be able to to spot all of the mitstakes

How many bricks does it take to complete a building that is 15 feet wide, 30 feet deep, and 12 feet tall made of brick?