what does the below rebus means?

Before the start of the car race, John and Jacob have the same amount of fuel in their car. With this fuel, John can drive for 4 hours while Jacob can drive five hours.
After a time they realize that the amount of fuel left in John's car is 1/4th of the fuel in Jacob's.

For how long they are racing?

How many cubic feet of dirt are in a hole of one foot deep, three feet long, and two feet wide?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

I cry without having a voice.
I fly without having wings.
I bite without having teeth.
I whisper without a mouth.

Who am I?

Why is it against the law for a man living in Delhi to be buried in Mumbai?

John was so frustrated to be the suspect of being a sleeper terrorist that he shoot himself right between the eyes with a revolver in his toilet. The revolver and the bullets were accurate. Minutes later John walks out of the toilet unharmed.
How can this be possible?

John’s parents have three sons: Snap, Crackle, and what’s the name of the third son?

There was a blind man. He had four socks in his drawer either black or white. He opened it and took out two socks. Now the probability that it was a pair of white socks is 1/2.

Can you find out the probability that he had taken out a pair of black socks ?

Count the number of lines in the image below ?