Which number should replace the question mark?

How many triangles are there in the picture below?

How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?

How can you spell "White of an egg" in one word?
Hint: I know you can spell coke, poke, and joke.

Something Extraordinary happened on May 6th 19778 at 12:34am what was that?

Imagine a box with two cogwheels, one big with 24 teeth and one small with 8 teeth. The big one is firmly attached to the center of the box which means it does not turn or move while the small one rotates around the big one.

How many times do you think that the smaller wheel will turn compared to the box when it turns once around the big one?

The person who makes it has no need for it; the person who buys it has no use for it. The person who uses it can neither see nor feel it. What is it?

Solve below rebus puzzle?

The more you take me, the more you leave me behind.
Who Am I?

The following question it puts forth you:

25 - 55 + (85 + 65) = ?

Then, you are told that even though you might think it's wrong, the correct answer is actually 5!

Whats your reaction to it? How can this be true?