Replace the question mark with the correct number.

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?

There once were seven dwarfs who were all brothers. They were all born two years apart. The youngest dwarf is seven years old. How old is his oldest brother?

On one occasion, A Boy collects 71 rupees in form of 20 paise and 25 paise. He collects a total of 324 coins.

Can you tell me how many 20-paisa and 25-paisa he got?

Different lights make me strange by changing me into different sizes. What am I?

A boy and his father are caught in a traffic accident, and the father dies. Immediately the boy is rushed to a hospital, suffering from injuries. But the attending surgeon at the hospital, upon seeing the boy, says 'I cannot operate. This boy is my son.' How is this situation explained?

You have to put a letter on the following to make it a meaningful word. The only challenge is that you can't use 'E'.

S E Q U E N C _

How can I get the answer 24 by only using the numbers 8,8,3,3?

You can use the main signs add, subtract multiply and divide.

What country can make you shiver?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?