The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

Why is it against the law for a man living in Delhi to be buried in Mumbai?

In a box, there is a jumble of 7 red balls, 6 blue balls, 5 green balls, and 4 yellow balls. What is the minimum number of balls, will you have to pick up so that you have at least 4 balls of the same colour?

In an office's desk, you find a unique method that shows the current day of the month. Two numbered cubes are used to depict the current date.

Can you find out the numbers on both the cubes so that each date can be mentioned using them?

Please note that you have to use both the cubes to display any date. Thus the 1st day must be represented by 01 and so on.

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?

I never was there, I am always to be.
You have never ever seen me, not ever you will.
Yet I am the confidence of everyone.

Who Am I?

A gardener planted the Lemon trees in a mathematical ordered way (i.e. he planted a tree in rows).
He created a total of 19 rows of trees.

Note: There should be more than 2 trees to count as a row.

What is the minimum number of trees required by the gardener to have 19 rows of trees?

Why Wine Glass Stem is so long?

Name a key which is hardest to turn.