A Japanese ship is sailing in the Indian Ocean. The captain of the ship feels tired and decides to take shower to be rejuvenated. He goes to take the shower after keeping his diamond-studded Rolex watch and gold chain on the table.
When he comes back after 15 minutes, he finds them missing. There are 4 crew members on the ship and he calls them one by one to ask them what they were doing in that duration.

Following are the answers:
1. Crew 'A' who is the cook replies that he was cooking mutton for the crew members.
2. Crew 'B' who is a housekeeper tells that he was sleeping in his room.
3. Crew 'C' who is the engineer says that he was checking on the generator.
4. Crew 'D' who is another housekeeper says that he was correcting the hoisted flag that was put upside down.

It took only a couple of seconds for the captain to find the thief. Can you find the thief too?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

Look at the picture and find out which square is not linked with any of the other squares.

What is full of holes but still holds water?

What has many teeth, but cannot bite?

What is the centre of gravity?

If you read clockwise, you can form a word by inserting three missing letters in the picture given below. Can you do it?

81 x 9 = 801. What must you do to make the this equation true?

Count the number of triangles in the below picture?

You have two buckets of 11 liters and 6 litres.
How can you measure exactly 8 litres?