What is the Surname of Barbie Doll?

I am lying and I always lie. Tell me whether I am lying or telling the truth.

A train full of passengers goes through a tunnel. When the train comes out from the other end, there is no single person on the train.

How did it happen?

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

Forwards I am heavy, backward I am not. What am I?

The first box has two white balls. The second box has two black balls. The third box has a white and a black ball.

Boxes are labeled but all labels are wrong!

You are allowed to open one box, pick one ball at random, see its colour and put it back into the box, without seeing the colour of the other ball.

How many such operations are necessary to correctly label the boxes?

I have branches, but no fruit, trunk or leaves. What am I?

A Japanese ship was en route to a mission on foreign seas. The captain of the ship felt tired and thought of taking a bath. He went for taking the shower and removed his diamond ring and Rolex and kept them on the table. When he returned after taking the bath, he found that the ring and watch were stolen.

He called the five members of the crew whom he suspected and asked them what they were doing for the last 15 minutes.

The Italian cook (with a butcher knife in hand): I was in the fridge room getting meat for cooking.

The British Engineer (with a high beam torch in hand): I was working on a generator engine.

The Pakistani seaman: I was on the mast correcting the flag which was upside down by mistake.

The Indian Radio officer: I was trying to make a contact with the company to inform them about our position.

The American navigation officer: I am on night watch, so I was sleeping in my cabin.

Upon listening to them, the captain caught the lying member. Who do you think stole the valuables?

You can see it everyday, But cannot touch it at will. What is it?

A horse was tied to a rope 5 meters long and the horses food was 15 meters away from the horse. How did the horse reach the food?