I’m tall when I’m young, and I’m short when I’m old. What am I?

What is the four-digit number in which the first digit is one-third the second, the third is the sum of the first two, and the last is three times the second?

Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10

Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

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?

It is Secret Agent Bond Girl Friend's birthday but he is on a secret mission

Mr Bond has a secret device by which he can only use the below words for sending the message.

Dumbo, Nazi, Carrot, Ronda, Zambia, Racing, TinTin, Seou, Zareeba, Laltain, Saphire, Tar, Orphan, Audition, Biscotti.

Mr Bond sends the following message to her girlfriend:
Carrot Dumbo Nazi Racing Ronda Zambia TinTin Seou Laltain Zareeba Tar Biscotti Orphan Audition Snake

What does Mr. Bond's Message say?

Can you complete the sequence puzzle?

AR TA GE CA LE VI LI _

A man calls his dog from the opposite side of a river. The dog crosses the river without a bridge or a boat and manages to not get wet. How is this possible?

Consider all the numbers between 1 and 1 million. Among all these numbers, there is something very special about the number 8 and the number 2202. What is it?

After teaching his class all about Roman numerals (X = 10, IX=9 and so on) the teacher asked his class to draw a single continuous line and turn IX into 6. The teacher's only stipulation was that the pen could not be lifted from the paper until the line was complete.