Find a 9-digit number, which you will gradually round off starting with units, then tenth, hundred etc., until you get to the last numeral, which you do not round off. The rounding alternates (up, down, up ...). After rounding off 8 times, the final number is 500000000. The original number is commensurable by 6 and 7, all the numbers from 1 to 9 are used, and after rounding four times the sum of the not-rounded numerals equals 24.

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

How can you drop a raw egg from a height onto a concrete floor without cracking it?

There are nine dots in the picture that has been attached with this question. Can you join all the dots by drawing four straight lines without picking up your pen?

I look at you, you look at me, I raise my right, you raise your left. What am I?

What has lots of eyes, but can’t see?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

There were two grandmothers and their two granddaughters.
There were two husbands and their two wives.
There were two fathers and their two daughters.
There were two mothers and their two sons.
There were two maidens and their two mothers.
There were two sisters and their two brothers.
Yet there are only six, who are buried here,
All are born legitimate and relationships clear.
How can this happen?

How high do you have to count before you use the letter “a” in the English spelling of the whole number?

Why despite killing dozens of people Charley and Wilma were not punished?