They have no flesh nor feathers nor scales nor bones. Yet they have fingers and thumbs of their own. What are they?

I’m as small as an ant, as big as a whale. I’ll approach like a breeze, but can come like a gale. By some I get hit, but all have shown fear. I’ll dance to the music, though I can’t hear. Of names I have many, of names I have one. I’m as slow as a snail, but from me you can’t run.

What am I?

A wholesale merchant came to me one day and posed this problem. Every day in his business he has to weigh amounts from one pound to one hundred and twenty-one pounds, to the nearest pound. To do this, what is the minimum number of weights he needs and how heavy should each weight be?

A book has 500 pages:

The 1st page says “Exactly 1 page in this book is false.”
The 2nd page says “Exactly 2 pages in this book are false.”

The 500th page says “Exactly 500 pages in this book are false.”

Can any of the pages be true?

7 people had the following conversation.

A: The day after tomorrow is Wednesday.
B: No, today is Wednesday.
C: Both of you are wrong, Wednesday is tomorrow.
D: Today is neither Monday, nor Tuesday, nor Wednesday.
E: I am pretty sure that Thursday was yesterday.
F: No, yesterday was Tuesday.
G: All I know, is yesterday wasn’t Saturday.

Only one of them is telling the truth. On which day did the argument took place?