What is the fastest way to double your money?

If,
29 - 1 = 30
9 - 1 = 10
14 - 1 = 15

Based on similar logic, Can you prove that the below algebraic equation is true?
11 - 1 = 10 ?

81 x 9 = 801. What must you do to make the this equation true?

Can you solve the below geography rebus by decoding the below rebus ?

Transform the word THINK into BRAIN while changing only one letter at a time in a manner that each of the word in the process is a real word!!!

In the image below, you can see two glasses and two matchsticks.You need to move four matchsticks in such a manner that the crosses come inside the glasses. Note: you cannot move the crossed.

Jenifer is learning to drive her car. She went down a one way lane and in the wrong direction. But she do not break any law.

How come ?

What Does this text mean:

important=important

Why do Chinese men eat more rice than Japanese men do ?

Cristina was born in 1888. She just had her 30th birthday today how did that happen?