What is full of holes but still holds water?

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?

What am I?

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

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?

What came first, the chicken or the egg?

Four people need to cross a rickety bridge at night. Unfortunately, they have only one torch and the bridge is too dangerous to cross without one. The bridge is only strong enough to support two people at a time. Not all people take the same time to cross the bridge. Times for each person: 1 min, 2 mins, 7 mins and 10 mins. What is the shortest time needed for all four of them to cross the bridge?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

Replace the question mark with the correct number in the below-given picture?

He digs out tiny caves and stores gold and silver in them. He also built bridges of silver and made crowns of gold. They are the smallest you could imagine. Sooner or later everybody needs his help, yet many people are afraid to let him help them. Who is he?