What is always in front of you but can’t be seen?

It spends most of its day eating white, but when it’s quick enough, it gets to eat fruit and sometimes some blue things. It’s in a dark room, where the walls are blue, it runs from a ghost that roams the halls and haunts it all the time. What is it?

I am a five-letter word and people eat me. If you remove the first letter I become an energy form. If you remove the first two letters, I am needed to live. Scramble the last three letters and I am a drink. What word am I?

How many times can you subtract the number two from the number fifty?

In a jungle where there are no street lights or any other artificial source of lights, I notice a black snake crossing the road.
How did I get sight of the snake?

Which wheel of car does not rotate when you turn your car right?

A landlord calls both of his sons and tells them that their horses will now decide who will transfer the inheritance. He tells them to race along the land till the end and the one whose horse will be slower will win and be the heir to all the property.

Both of them keep wandering for days but to no result. Then they ask a wise man regarding it. The man advises them on the matter after which they jump on the horses and race as fast as they can till the end. Why did they do it?

What did the wise man say?

If eleven plus two equals one, what does nine plus five equal?

I never stop running even when I standstill. If I am formed by joining two identical bodies together, can you guess who I am?

If it took eight men ten hours to build a wall, how long would it take four men to build it?