The more of this there is, the less you see. What is it?

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

Remove two matchsticks to make the below equation correct.

Find The Next Number in this series.
1, 2, 6, 42, 1806 ?

Can you find the 09 errors in the picture below?

What makes this number unique: 8,549,176,320?

Christina, Allison and Lena are 3 daughters of John a well-known Mathematician, When I asked John the age of their daughters. He replied "The current age of her daughters is prime. Also, the difference between their ages is also prime."

How old are the daughters?

what does the below rebus means?

You’ll find me on Mercury, Earth, Mars, Jupiter, Saturn, and Uranus. But never Neptune, or Venus. What am I?

In the picture, you can see a chess board. On the top left position, the K marks a knight. Now, can you move the knight in a manner that after 63 moves, the knight has been placed at all the squares exactly once excluding the starting square?