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

I am the fastest animal but cannot climb the tree. What am I?

Six glasses are in a row. The first three are filled with milk and the last three are empty. By moving only one glass, can you arrange them so that the full and the empty glasses alternate?

No matter how little or how much you use me, you change me every month. What am I?

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

Your job is to measure 45 minutes if you have only two cords and matches to light the cords.

1. The two cords are twisted from various materials, so their different segments can burn at different rates.
2. Each cord burns from end to end in exactly one hour.

Describe your way of measuring the 45 minutes.

Can you solve this picture maths equation?

What is always in front of you but can’t be seen?

Which is the smallest number that you can write using all the vowels exactly once?

What has one letter and starts with an E?