A man has a barrel filled with oil that weighs 100 pounds, and then he puts something into it. Now the barrel weighs less than 100 pounds. What did he put in the barrel?

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

Which statement is true out of the following?
One statement here is false.
Two statements here are false.
Three statements here are false.

What is next number in the pattern below:

131 517 192 123 ?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

I cannot talk, but I always reply when spoken to. What am I?

John was going on a jungle trip. He asked his wife to pack something to eat, something to drink and something to burn if he feels cold in the jungle. When John opens the backpack he found just one thing in the bag. What was it?

There are three boxes which are labeled as Rs100, Rs150, and Rs200. One box contains two notes of Rs. 50. The second box contains one note of Rs50 and one note of Rs100 The third box contains two Rs. 100 notes. All boxes are labeled incorrectly.

What is the minimum number of boxes you must check in order to label all boxes correctly?

You want to boil a two-minute egg. If you only have a three-minute timer (hourglass), a four-minute timer and a five-minute timer, how can you boil the egg for only two minutes?

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