You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

How high do you have to count before you use the letter “a” in the English spelling of the whole number?

A person is found murdered in his Chamber. When the crime scene is investigated, the Investigator find out that there is a calendar on which the victim has written a few numbers with his blood. The numbers are 4, 11, 11 and 4.

There are four suspects in the murder, John, Jacob, Anna and Lee. Can you find out who is the murderer?

Luis Garavito killed Density x Volume.

Who is Luis Garavito ?

John named his first son Alpha, second Beta, third Charlie and fourth Delta. What is the fifth son's name?

You can win me and lose me but never buy me
You can not eat me and never want to part with me
I can make you cry or bring you joy
I am not a machine and definitely not a toy
You keep me but i am not forever just yours
You might find me in a case or on a shelf next to a vase
I am hard and i am tall if you bump me i am sure to fall
I am made of different materials and am at many events
If your lucky and fight hard I might be yours
What am I ?

What do you call a fish without an eye?

I have branches, but no fruit, trunk or leaves. What am I?

If,
29 - 1 = 30
9 - 1 = 10
14 - 1 = 15

Based on similar logic, Can you prove that the below algebraic equation is true?
11 - 1 = 10 ?