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

What happened when the wheel was invented?

What is the Surname of Barbie Doll?

Two boys wish to cross a river. The only way to get to the other side is by boat, but that boat can only take one boy at a time. The boat cannot return on its own, there are no ropes or similar tricks, yet both boys manage to cross using the boat.

How?

There is something which is always coming but never arrives?

By what process could you make a 'Tea-Table' into food?

In the city of Brain Teasers, 5% of people do not list their phone numbers. Now if we select random 100 people from the phone directory, then how many people selected will have unlisted phone numbers?

Can you find the missing letter in the sequence?
S - T - I - L - ? - T - F - Y - C

I had an infinite supply of water and 5 litres and 3 litres jars.

How would you measure exactly 4 litres in the least number of steps?

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 ?