How can you take 2 from 5 and leave 4?

Count the number of triangles in the given picture.

I can be made.
I can be cracked.
I can be told.
I can be played.

Who am I?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

I have lakes with no water, mountains with no stone and cities with no buildings. What am I?

Can you fill the blank with the correct number?

6 30 870 756030 _____

You are given with the following sum. Each of the letters can be decoded as a digit. If we tell you that D = 5, then can you solve it entirely?

DONALD
+GERALD
=ROBERT

our enemy challenges you to play Russian Roulette with a 6-cylinder pistol (meaning it has room for 6 bullets). He puts 2 bullets into the gun in consecutive slots, and leaves the next four slots blank. He spins the barrel and hands you the gun. You point the gun at yourself and pull the trigger. It doesn't go off. Your enemy tells you that you need to pull the trigger one more time, and that you can choose to either spin the barrel at random, or not, before pulling the trigger again. Spinning the barrel will position the barrel in a random position.

Assuming you'd like to live, should you spin the barrel or not before pulling the trigger again?

Can anyone tell me a word in the English dictionary which has a silent 'z'?

With the help clues provided in the image, can you find the 5 digit key?