Find the number of squares in the below picture

Can you solve the below rebus?

What is the Surname of Barbie Doll?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

Can you count the number of quadrilaterals in the picture below?

Can you find out who is the kidnapper in below Picture and why, Explain ?

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 does this rebus picture means ?

Replace all '*' with digits 1, 2, 3, 4, 5 and 6 to make below statement true.

* *
x *
=====
* * *

In the Chess Board picture below white army is arranged. You need to add a black army on the board such that no piece is under any threat.
Note: Army comprised of 1 king, 1 queen, 2 rooks, 2 bishops, 2 knights, and 8 pawns.