What does this simple rebus mean?

Find the number of squares in the below-given picture.

Find the next number in the series below

21 32 54 87 131 ?

Can you make four (4) nines (9) equal 100?

A woman is sitting in her hotel room and hears a knock at the door. She opens the door to see a man whom she’s never met before. He says, “I’m sorry, I have made a mistake, I thought this was my room.” He then goes down the corridor and into the elevator. The woman goes back into her room and calls security. What made the woman so suspicious of the man?

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

We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?

John is on an island and there are three crates of fruit that have washed up in front of him. One crate contains only apples. One crate contains only oranges. The other crate contains both apples and oranges.

Each crate is labelled. One reads 'apples', one reads 'oranges', and one reads 'apples and oranges'. He know that NONE of the crates have been labeled correctly - they are all wrong.

If he can only take out and look at just one of the pieces of fruit from just one of the crates, how can he label all of the crates correctly?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

Decode below three cipher riddles:

26 L of the A
7 D of the W
1000 Y in a M