The centre of the third figure is empty. What digit should fit inside?

An exterior architect is asked by a builder to plant seven trees in a manner that there are exactly six rows of trees in a straight line and each row has three trees in particular.

How will he do it?

Why is the Hole below a Lock?

A man and a dog were going down the street. The man rode, yet walked. What was the dog’s name?

What runs around the whole yard without moving?

A girl says this to her best friend: “I was born in 1955, and I celebrated my 17th birthday last weekend.” Her best friend thinks she’s lying, but she’s actually correct. How is that possible?

What is more useful when it is broken?

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 ?

What does this Rebus Picture mean?

10+10 and 11+11 can give you the same answer.

Explain how?