Can you find out the missing number?

? 4 5 3 5

9 5 7 10 3

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

Outside a tattoo artist's shop, there was a signboard which read 'I make tattoos on only them who do not tattoo themselves'.

Reading it what do you think, does the tattoo artist tattoo himself?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

Things are just as they seem, right? Well, check again.
Can you count the number of tigers in this picture ?

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

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

One day, I thought of ways that can be used for creating a palindrome. So I decided that I will turn into a larger number by adding the reversed digits to the original number and keep doing it till I finally obtained a palindrome.

I am not sure if this process will always result in a palindrome eventually but I was able to produce a four-digit palindrome. Can you guess my starting number?

Find the missing letter in the last circle logically in the given below picture.

what does the below math rebus puzzle mean?