Find out a multi-digit number that if multiplied by the number 9 or any of its multiplications products (i.e. 18, 27, 36, 45,..) will result in the multiplication factor repeated (n) number of times.

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

Count the number of triangles in the given picture.

Get total of 120 by using five zeros 0,0,0,0,0 and any one mathematical operator.
Do you ?

I look at you, you look at me, I raise my right, you raise your left. What am I?

Double it and multiply it by 4. Then divide it by 8 and you’ll have it once more. What number is it?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

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!!!

Using four sevens (7) and a one (1) create the number 100. Except for the five numerals, you can use the usual mathematical operations (+, -, x, :), root and brackets ()

There is something which you can be arrested for attempting but not for successfully completing.