What does it mean?

Why is the Hole below a Lock?

When is the top of a mountain similar to a savings account?

This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?

Name the three-letter word that can complete the below words:

A) L O _ _ _ E
B) E D U _ _ _ E
C) _ _ _ E R
D) _ _ _ T L E

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

What is the last thing you take off before bed?

Place the numbers from 1 to 9 in the circles in a manner that each side of the triangle sums up to 17.

An octopus has 8 legs. A hippogriff has 6 legs and 2 pairs of wings. A sphinx has 6 legs and one pair of wings. Now we have all 3 kinds and a total of 18 insects in a cage. We have a total of 118 legs and 20 pairs of wings. How many insects do we have of each kind?

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 ?