What work can one never finish?

What is the next number in the series?

15 29 56 108 208 ?

Jenifer is learning to drive her car. She went down a one way lane and in the wrong direction. But she do not break any law.

How come ?

What three numbers, none of which is zero, give the same result whether they’re added or multiplied?

A hen, a dog, and a cat are stolen. Three suspects are arrested named Robin, Steve, and Tim. The police are sure that all of them stole one of the animals but they don't know who stole which animal.

Sherlock Holmes is appointed to identify and is provided with the following statements from the investigation.

Robin - Tim stole the hen
Steve - Tim stole the dog
Tim - Both Robin and Steve are lying. I neither stole a hen nor a dog.

Sherlock is somehow able to deduce that the man who stole the cat is telling a lie and the man who stole the hen is telling truth.

Can you help him find out who stole which animal?

Out of three Friends John, Jacob and Jonny one of them is a king, one is a bureaucrat, and one is a Spy.

The king always tells the truth, the bureaucrat always lies, and the Spy can either lie or tell the truth.

John says: Jonny is a bureaucrat
Jacob says: John is a king
Jonny says: I am a Spy

Tell me, Who is the king, who is the bureaucrat, and who is the Spy?

Accidentally, two trains are running in the opposite direction and enter a tunnel that is 200 miles long. A supersonic bird that has fled the lab and taken shelter in the tunnel starts flying from one train towards the other at a speed of 1000 mph. As soon as it reaches the second train, he starts flying back to avoid collision and meets the first train again at the other end. The bird keeps flying to and fro till the trains collide with each other.

What is the total distance that the supersonic bird has traveled till the trains collided?

Why Aeroplane windows are round?

There are five vowels (a, e, i, o, u) in the English language.
Can you tell us a word that contains all these vowels?

As you can see that fifteen matches have been used to form an arrangement. What you have to do is remove any six of them to make them ten.