Why is Saturday stronger than Monday?

This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

By moving just one matchstick, you need to make the below statement true. Can you do it?

What is the centre of gravity?

Name one eight-letter word with 'kst' in the middle, 'in' the beginning, 'and' at the end.?

Astrology starts with the alphabet A, Biology starts with B, Psychology with P and Limnology with L.

Can you find an "ology" that begins with a P?

I am not alive, but I grow; I don't have lungs, but I need air; I don't have a mouth, but water kills me. What am I?

I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

A number with an interesting property:

When I divide it by 2, the remainder is 1.
When I divide it by 3, the remainder is 2.
When I divide it by 4, the remainder is 3.
When I divide it by 5, the remainder is 4.
When I divide it by 6, the remainder is 5.
When I divide it by 7, the remainder is 6.
When I divide it by 8, the remainder is 7.
When I divide it by 9, the remainder is 8.
When I divide it by 10, the remainder is 9.

It's not a small number, but it's not really big, either.
When I looked for a smaller number with this property I couldn't find one.

Can you find it?