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

What has many keys but can’t open a single lock?

Can you count the number of blocks in the picture below?

Can anyone tell me a word in the English dictionary which has a silent 'z'?

What building has the most stories?

One night, a woman receives a call from the police. They tell her that her husband was murdered and that she should come to the crime scene as soon as possible. The woman drops the phone, shocked, and drives 20 minutes to the crime scene. As soon as she reaches the crime scene, the police arrest her and she is convicted of murder. How do the police know she committed the crime?

A doctor and a boy were fishing. The boy was the doctor’s son, but the doctor was not the boy’s father. Who was the doctor?

John went to buy some expensive, foreign chocolates. He only had Rs 100 with him. When he reached the shop, he got out and know that on those chocolates, there was a 15% import duty and 5% VAT.

How much worth chocolate should he buy so that he can accommodate it in Rs 100?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

What does the following represent?

N N N N N N N

A A A A A A A

C C C C C C C