Before Mount Everest was discovered, what was the highest mountain in the world?

What does this Rebus Picture mean?

A man dies of old age on his 25 birthday. How is this possible?

Why is the Hole below a Lock?

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?

Imagine you are in a room with no windows or doors. How will you get out?

John has eleven friends. He has a bowl containing eleven apples. Now He wants to divide the eleven apples among his friends, in such a way that an apple should remain in his bowl.
How can He do it?

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

What do you get if you add 2 to 100 four times?

I have a five and a three-gallon jar. Assuming there is an infinite supply of water, how can I measure one-gallon water?