I am not alive, but I grow; I don't have lungs, but I need air; I don't have a mouth, but water kills me. What am I?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

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?

How many bananas can you eat if your stomach is empty?

If you read clockwise, you can form a word by inserting three missing letters in the picture given below. Can you do it?

In the image given, you can find several triangles. Can you count them all?

I live in a bowl. I can swim. I have a tail. I also have fins and big eyes. What am I?

Count the squares in the matchstick puzzle below?

1 dollar = 100 cent
= 10 cent x 10 cent
= 1/10 dollar x 1/10 dollar
= 1/100 dollar
= 1 cent

=> 1 dollar = 1 cent

solve this tricky problem?

What is black when you buy it, red when you use it, and gray when you throw it away?