What does below pictogram mean?

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?

Using the clues below, what four numbers am I thinking of?

The sum of all the numbers is 31.
One number is odd.
The highest number minus the lowest number is 7.
If you subtract the middle two numbers, it equals two.
There are no duplicate numbers.

What is a word made up of 4 letters, yet is also made up of 3. Sometimes is written with 9 letters, and then with 4. Rarely consists of 6, and never is written with 5.

No one wants to have it, but if one got it, he does not want to lose it. What is It?

Divide 110 into two parts so that one will be 150 per cent of the other. What are the 2 numbers?

Replace the letters of words with a number so that the below equation holds true

BASE +
BALL
---------
GAMES
----------

How many times do a clock's hands overlap in a day ?

Name a key which is hardest to turn.

A man dies of old age on his 25 birthday. How is this possible?