ENEMY = 2 * LINK
LINK + 2 = HELL

Then what will be TAXI + HELL? Select from the options below:
a) ROTTEN
b) DANGER
c) HEAVEN
4) MORTAL

What is more useful when it is broken?

It can't be seen, can't be felt, can't be heard, and can't be smelt.
It lies behind stars and under hills, And empty holes it fills.
It comes first and follows after, Ends life, and kills laughter.
What is it?

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

A boy purchased a book from a bookkeeper and gave him $100.
The cost of the book is $50 but the bookkeeper has no change, so he gets the change from the next shop and returns the boy his $50.

After some time the next shopkeeper came with the $100 note and told the bookkeeper that the note was a fraud, so he took the money back.

How much loss did the bookkeeper face?

I am a five-letter word and comprises two different vowels and three same consonants. I am so strong that I can spoil your entire work.

Can you find out who am I?

What does below chemistry rebus means?

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?