How many words can a pen with half refill write?

John is found dead in his office at his desk. The police have narrowed the suspects down to three people: Mrs. Jacob, John’s wife Hena and his business partner Jason . All three visited John on the day of his murder, but all three provide the police with stories of explanation as to the reason for their visit.
Police found John with his wrist watch still on his right arm, a torn up picture of his wife laying on the floor beside the trash can, and an ink pen in his right hand. On the desk, the police found a name plate, a telephone that was off the hook, and a personal calendar turned to the July 5th page with 7B91011 written on it. After examining this evidence, the police knew their suspect. Who was it ?

What kind of band never plays music?

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 ?

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

Which is Odd One Out and why?

4377

3954

9862

8454

9831

Can you name an animal whose killing cannot be performed without spilling your own blood?

What always comes into a house through the keyhole?

In my garden, I have many trees but only one of them is the mango tree. In these mango trees, there are some mangoes(as expected).

But after a strong wind, there are neither mangoes on the tree nor on the ground. Explain?

That attorney is my brother, testified the accountant.

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

Who is lying?