When it's bad luck to meet a black cat?

Complete the following series. It.s very logical:

1, 4, 5, 6, 7, 9, 11, __?

What has many teeth, but cannot bite?

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?

You’ll find me on Mercury, Earth, Mars, Jupiter, Saturn, and Uranus. But never Neptune, or Venus. What am I?

Can you tell a 3D object that has just two surfaces?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

Can you complete the sequence?

192, 021, 222, 324, 252, 627, 2__, 9__?

You have 10 balls with you. A friend of yours out of nowhere asks you to place those ten balls in five lines such that each of the lines has exactly 4 balls on them. He needs to check your intelligence. Prove him by doing the task.

Count The number of F's in the paragraph below:

"FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC STUDY COMBINED WITH THE EXPERIENCE OF YEARS"