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.

I am taken from a mine and shut up in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

The owner of a popular clothing store comes up with his own method of pricing items. A vest costs $8, socks cost $10, a tie costs $6, and a blouse costs $12. Using the owner’s method, how much would a pair of underwear cost?

What came first, the chicken or the egg?

Which is the correct shadow of the bird?

Which is Odd One Out and why?

4377

3954

9862

8454

9831

What can you hold in your right hand, but never in your left hand?

A sundial has the fewest moving parts of any timepiece. Which has the most?

What has 13 hearts but no other organs?