How can a man go eight days without sleep?

We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?

Below is the sum of symbols in each row and column in the figure. Analyzing the figure, can you find out the value of the symbols?

why number 8549176320 is one of a kind?

Place a mathematical symbol between the numerals 5 and 9 in such a way that the resulting number is greater than 5 but smaller than 9.

A red house is made out of red bricks. A yellow house is made out of yellow bricks. And, a blue house is made out of blue bricks. So, what is a greenhouse made of?

Four men were in a boat on the lake. The boat turns over, and all four men sink to the bottom of the lake, yet not a single man got wet! Why?

A few friends are enjoying their sea voyage in a boat full of apples. On the way, they felt hungry and thus decided to eat the apples. Together, they ate two dozen of apples. When they have eaten the apples, will there be any change in the water level?

There are four people in a house. A fireman, an athlete, an old woman, and a drunk guy. The house catches fire and before the fact is known, it is too late. All they know is that the entire house is in flames and it will collapse exactly after twelve minutes. Now they can move out of the house but for that, they will have to pass the hallway which is entirely blazing with flames. Thus to move, one must carry a fire extinguisher to keep the flames away. Seeking the burnt wooden floor, only two people can run through that hallway at one time. But for others to go, one must return back with the fire extinguisher. The fireman is trained for such tasks and can run through the hallway in a minute. The athlete can make it in a couple of minutes. The old woman can run slowly and will cover the hallway in four minutes. The drunk guy will take five minutes to run through it. If all of them can make it through the hallway in twelve minutes, all of them will be saved. When two move together, they will run at the speed of the slower ones.

How will all four of them manage to run to safety?

While house hunting in London, I came across a very good leasehold property Discussing the lease the landlady told me:

'The property was originally on a 99 years lease and two-thirds of the time passed is equal to four-fifths of the time to come. Now work it out for yourself and see how many years are to go!