A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

What can go up a chimney down, but can’t go down a chimney up?

I guess 76.8% of readers will like this riddle.

What's the least number of people should read this post?

When a clock is observed, the hour hand is at a minute mark and the minutes hand is six minutes ahead of it.

When the clock is observed again after some time, the hour hand is precisely on a different minute mark and the minute hand is seven minutes ahead of it.

Can you calculate how much time has elapsed between the two observations?

How many sides does a circle have?

Can you place six X (crosses) in below board without making three in a row in any way ?

There is one thing that goes round the house and also inside the house but never even share a brief touch. What is it?

I’m light as a feather, yet the strongest person can’t hold me for five minutes. What am I?

What is the end of everything?

The day before yesterday I was 25 and the next year I will be 28. This is true only one day in a year. What day is my birthday?