Replace the question mark with the number below given a simple math problem.

I am white when I am dirty, and black when I am clean. What am I?

There are five vowels (a, e, i, o, u) in the English language.
Can you tell us a word that contains all these vowels?

What does the following BrainBat signifies?

ABCDEFGHIJKLMNOPQRSTUVWYZ

QQQQQQQQQQQQQQQQQQQQQQQQQ.

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

What do you answer even though it never asks you questions?

We have four gears with below features=> Both Gear A and D has 60 teeth=> Gear B has 40 teeth=> Gear C has 20 teeth=> Every two minutes, Gear B makes 25 full turns.What is the relative speed of Gear A and Gear B?

Decode below three cipher riddles:

26 L of the A
7 D of the W
1000 Y in a M

Find the 8 in the below-given Image.

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!!!