why number 8549176320 is one of a kind?

Make the seating arrangement of 10 children in such a way that there are 5 rows with 4 children in each row.

Move three sticks of the spiral below to form a square.

You can see it everyday, But cannot touch it at will. What is it?

When 99 is considered higher than 100?

There were three women in all the swimming costumes!
One was happy and the other two were sad!
The happy one was crying and the sad ones were smiling.
Why was this?

It belongs to you, but other people use it more than you do. What is it?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

What does the below rebus riddle means?

You are given with the following sum. Each of the letters can be decoded as a digit. If we tell you that D = 5, then can you solve it entirely?

DONALD
+GERALD
=ROBERT