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

What does the following BrainBat signifies?

ABCDEFGHIJKLMNOPQRSTUVWYZ

QQQQQQQQQQQQQQQQQQQQQQQQQ.

If there are fifteen crows on a fence and the farmer shoots a third of them, how many crows are left?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

Can you find the 09 errors in the picture below?

There is a box full of marbles,
all but two are blue,
all but two are green,
and all but two are red.

How many marbles are in the box?

If 1+9+8=1, what is 2+8+9?

What kind of storm is always in a rush?

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

Why do we preferably have round manhole covers and not square ones?