Solve below rebus puzzle?

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

The teacher told the student that if he told a lie then he will be expelled from school and if he told the truth then he still is expelled from school.

What can a student say to prevent his being expelled from school?

Out of the nine cats that you can see in the picture, there are only two that are completely identical. Can you find them out?

Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

Can you find the key in the picture below?

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

What is the next number in this matchsticks series riddle?

There is a box full of marbles,
all but two are blue,
all but two are green,
and all but two are red.

How many marbles are in the box?

This is a simple one. You just have to count the number of Fs in the given sentence.

Finished Files are the result of years of scientific study combined with the experience of years.

How many did you count?