Replace the question mark with the correct number in the below-given picture?

The dirtier I get, the whiter I look. Who am I?

What is 3/7 chicken, 2/3 cat and 2/4 goat?

Find the value of "a" by solving the maths equation in the picture below:

A boy was at a carnival and went to a booth where a man said to the boy, "If I write your exact weight on this piece of paper then you have to give me $50, but if I cannot, I will pay you $50." The boy looked around and saw no scale so he agrees, thinking no matter what the carny writes he'll just say he weighs more or less. In the end the boy ended up paying the man $50. How did the man win the bet?

Buy me, smell me or deliver me, I do not change.

Who am I?

John can place six large boxes or nine small boxes into a carton.

Can you find out in how many cartons can he place sixty-six boxes in total?

You Are Highly Attentive If You Can Spot A Hat In This Bathroom In 9 Seconds!

You are given a cube that is made with the help of 10x10x10 smaller cubes summing up to a total of 1000 smaller cubes. You are asked to take off one layer of the cubes.
How many remain now?

Can you count the number of squares in the figure below?