John was writing his first book. After saving the document, he locked his laptop with a password and mentioned some phrases for the hint box.

A friend of his tried opening his laptop but found out that it was password protected. Following is the hint that appeared.
1 mobile 3 books 2 roars 1 night 4 balls 2 lighters 1 ghost 1 hat 3 watches.

Can you help him in cracking the password?

Two guards were on duty outside a barracks. One faced up the road to watch for anyone approaching from the North. The other looked down the road to see if anyone approached from the South. Suddenly one of them said to the other, "Why are you smiling?"

How did he know his companion was smiling?

If eleven plus two equals one, what does nine plus five equal?

There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?

There is a box full of marbles,
all but two are blue,
all but two are green,
and all but two are red.

How many marbles are in the box?

We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?

13 decks of cards have been mixed. What is the minimum number of cards that must be taken out from the above-mixed cards to guarantee at least one 'four of a kind?

What number comes next in the series?

5 15 5 18 5 24 14 20 _

At Delhi Cricket Clubhouse, there were four kids(Kohli, Yuvraj, Pant, and Dhoni) ages 1,2,3 and 4 and have 1,2,3 and 4 cricket balls in different orders.

We know the following facts:

Kohli has more cricket balls than his age.
Dhoni is older than Yuvraj.
One child has the same number of cricket balls as his age.
Pant has fewer cricket balls than Dhoni.
A child aged 3 has two cricket-balls.

Pant is the youngest.

Can you determine the age of the children and the number of cricket balls they have?

You have two strings whose only known property is that when you light one end of either string it takes exactly one hour to burn. The rate at which the strings will burn is completely random and each string is different. How do you measure 45 minutes?