What is full of holes but still holds water?

Count the Triangle in the figure given below:

I have eight fingers and two thumbs but I do not live. What Am I?

What does the following represent?

N N N N N N N

A A A A A A A

C C C C C C C

A wealthy man lives alone in a small cottage. Being partially handicapped he had everything delivered to his cottage. The mailman was delivering a letter one Thursday when he noticed that the front door was ajar. Through the opening he could see the man's body lying in a pool of dried blood. When a police officer arrived he surveyed the scene. On the porch were two bottles of warm milk, Monday's newspaper, a catalog, flyers, and unopened mail. The police officer suspects it was foul play. Who does he suspect and why?

What is next number in the pattern below:

131 517 192 123 ?

Using Only Five 5's and any mathematical operator make sum as 37

You are in a room that has three switches and a closed door. The switches control three light bulbs on the other side of the door. Once you open the door, you may never touch the switches again. How can you definitively tell which switch is connected to each of the light bulbs?

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?

Which is the correct shadow of the bird?