What's the only room from which no one can enter or leave

John is the son of Jacob.
So,
Jacob is the_____of John's father?

On the dull night when the blonde was dozing, she heard an odd clamour and she saw that there was a bizarre man with a gun simply outside her home. So she raced to the telephone to call the police, however, she can't dial 911. Why?

On a magical land of Mexico , all the animal in the land are rational.

There are 10 tigers and one goat.
Tiger can eat goat but since it's a magical land , the tiger who eats the goat , turns into goat and then can be eaten by the remaining tiger(s).

If we leave them for some time then how many goat and tiger will be there , when we come back ?

That attorney is my brother, testified the accountant.

But the attorney testified he didn't have a brother.

Who is lying?

What does this Rebus Picture mean?

Solve below rebus puzzle?

Take one out and scratch my head, I am now black but once was red. What am I?

There's one "sport" in which neither the spectators nor the participants know the score or the leader until the contest ends.

What is it?

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