What has one letter and starts with an E?

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

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

Why 1729 is a magic number? Answer Logically.

Before Mount Everest was discovered, what was the highest mountain in the world?

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

I am a white box having no key or lid.
Yet there is a golden treasure inside it.

What Am I?

In four steps you need to move the word 'cold' From 'warm' by replacing one alphabet at a time such that every word formed at each step is acceptable in English Dictionary.

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

1 rabbit saw 9 elephants while going to the river. Every elephant saw 3 monkeys going toward the river. Each monkey had 1 parrot in each hand. How many animals are going towards the river?