I am white when I am dirty, and black when I am clean. What am I?

A journalist was investigating a sacred cult in the jungles of Africa when he was caught by one of the person. He was confined in a cave till the leader arrived. The leader told him that he need to tell him a statement. If he thinks the statement is true, then the journalist head will be chopped off. If he thinks that the statement is false, his head will be smashed with a hammer.

What statement did the journalist make to survive?

Why is the Hole below a Lock?

I was speeding and ran through a stop sign, yet two traffic officers who were there do nothing about it.

why?

You are in a room that has three switches and a closed door. The switches control three light bulbs on the other side of the door. Once you open the door, you may never touch the switches again. How can you definitively tell which switch is connected to each of the light bulbs?

At my favorite fruit stand,
an orange costs 18,
a pineapple costs 27,
and a grape costs 15.
Using the same logic, can you tell how much a mango costs?

Take 9 from 6, 10 from 9, 50 from 40, and leave 6.

How Come ??

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

What is the word or phrase?

There was a competition where the contestants had to hold something. At the end of the event, the winner was a person who had no hands or feet. What was it that the contestants had to hold?