What is full of holes but still holds water?

It is always ahead of me yet I can never see it. What is it?

The richest man in the city Mr Rechard is kidnapped. James Bond is appointed to the case. At the crime scene, a note is found written by Mr Richard. The note read:

"First of January, Fourth of October, Fifth of March, Third of June."

James Bond knew that somehow, the killer's name was hidden in the note. The following were the suspects:

Jack Richard, the son and the heir of property.
John Jacobson, the employee of Richard.
June Richard, the wife of Richard.

James Bond took only a few moments to deduce the killer's name. Can you tell who was the killer?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

Name a key which is hardest to turn.

It's a test that will check your IQ.

Suppose you have one 11 minute hourglass and one 13 minute hourglass.

Can you measure exactly fifteen minutes using them ?

What does this Rebus Picture means ?

Why do people go to bed?

Place a mathematical symbol between the numerals 5 and 9 in such a way that the resulting number is greater than 5 but smaller than 9.

Rahul decided to meet Simran so he boards a local train from Bombay station. Just after the station, there is a 1km long tunnel. The train starts and is now accelerating. Rahul is a claustrophobic guy, so what is the best position for him to sit?