Why do we preferably have round manhole covers and not square ones?

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

Find out a multi-digit number that if multiplied by the number 9 or any of its multiplications products (i.e. 18, 27, 36, 45,..) will result in the multiplication factor repeated (n) number of times.

A man and a dog were going down the street. The man rode, yet walked. What was the dog’s name?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

A river should be crossed by a father, a mother and their two sons and two daughters.
There are some rules that should be followed while crossing the river. There can be only two people in the raft while crossing. The daughters cannot be with their father unless there is the presence of the mother. The sons cannot be with their mothers unless the father is present. Unless the guard is on the board, the criminals cannot be with any of the family members. Only the adults like the father, the guard, and the mother knows to use the raft.

How will they cross the river?

What does man love more than life, and hate more than death or mortal strife; that which satisfied men want; the poor have, and the rich require; the miser spends, the spendthrift saves, and all men carry to their graves?

Count the number of balls in picture below:

What is the difference between a jeweller and a jailer?

A very interesting trivia question for all.

Why do men's shirts have their buttons on the right side and women's have buttons on the left-hand side?