2, 3, 5, 9, 17, _ What is the next number in the sequence?

What is the relationship between these matchstick pictures below?

What does the below mathematical rebus mean?

There are are five things wrong with this sentence; only geniuses will be able to to spot all of the mitstakes

A mules travels the same distance daily.
I noticed that two of his legs travels 10km and the remaining two travels 12km.
Obviously two mules legs cannot be a 2km ahead of the other 2.

The mules is perfectly normal. So how come this be true ?

What does below chemistry rebus means?

Can you find out which number multiplied by itself will give the output as 12345678987654321?

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

A few friends are enjoying their sea voyage in a boat full of apples. On the way, they felt hungry and thus decided to eat the apples. Together, they ate two dozen of apples. When they have eaten the apples, will there be any change in the water level?

There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?