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

Twice ten are six of us,

Six are but three of us,

Nine are but four of us;

What can we possibly be?

Would you know more of us?

Twelve are but six of us,

Five are but four, do you see?

What are we?

Replace each alphabet with the number (1-9) to make the below equation correct.

AB * C = DE - F = GH / I

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

If it took eight men ten hours to build a wall, how long would it take four men to build it?

One day, I thought of ways that can be used for creating a palindrome. So I decided that I will turn into a larger number by adding the reversed digits to the original number and keep doing it till I finally obtained a palindrome.

I am not sure if this process will always result in a palindrome eventually but I was able to produce a four-digit palindrome. Can you guess my starting number?

You need to move three matchsticks to form three squares. Can you do it?

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?

If 24H in a D => 24 hours in a day.
What does "64S on CB" stand for?

If six children and two dogs were under an umbrella, how come none of them got wet?