Why is the longest human nose just 11 inches?

Here is a mathematical expression that also secretly tells a movie name. What movie is that?

Once upon a time, there was a castle on a square island. The entire island was surrounded by a 14m wide trench. The Romans had wanted to invade the castle and had brought a few wooden planks along with them to facilitate themselves in crossing the moat. The planks were however found to be only 13m long.

The Romans still managed to cross the trench. How did they do it?

Assume there are approximately 5,000,000,000 (5 billion) people on Earth. What would you estimate to be the result, if you multiply together the number of fingers on every person's left hand? (For the purposes of this exercise, thumbs count as fingers, for five fingers per hand.) If you cannot estimate the number then try to guess how long the number would be.

Can you replace the question mark with the correct letter?

6 + 6 + 6 = N
7 + 7 + 7 = E
8 + 8 + 8 = R
0 + 0 + 0 = ?

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?

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

When we see 2 but call 10?

What jumps when it walks and sits when it stands?

In the given figure, you can see that four match sticks are used to form a square. Can you form five squares by using six matches?