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

I’m tall when I’m young, and I’m short when I’m old. What am I?

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

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

Be active and find the killer in the picture Riddle below.

A girl was sitting in her hotel room when she heard a knock on the door. She opened the door and found that a man was standing outside. The man said, "Oh! I am really sorry, I thought this was my room." He then walked through the corridor to the elevator. The girl did not know the man. She closed her door and called security asking them to apprehend the man. What made her suspicious of that man? He might have been genuinely mistaken.

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?

Which five letter word can be added at the end of below word to form a
valid word?

> Pin
> Check
> Boiling
> View

Suppose you are a girl candidate and sitting in an interview. Suddenly the interviewer asks you, 'What if one morning you wake up and find out that you are pregnant?

How will you reply to such a question?