Three doctors said that Bill was their brother. Bill says he has no brothers. How many brothers does Bill actually have?

Can you tell a 3D object that has just two surfaces?

Your job is to measure 45 minutes if you have only two cords and matches to light the cords.

1. The two cords are twisted from various materials, so their different segments can burn at different rates.
2. Each cord burns from end to end in exactly one hour.

Describe your way of measuring the 45 minutes.

Can you find out the smallest number that can be conveyed as the sum of three squares in three unique ways?

It belongs to you, but other people use it more than you do. What is it?

What do you see in the given picture?

John went to a parrot shop in Mexico, and the parrot owner told him that his parrot is so unique that he repeats everything he hears. John got excited and immediately bought the parrot. John went home and spoke many words, but the parrot does not repeat anything.
He went again to the parrot shop and complaint to the shopkeeper, but the shopkeeper never lied. Explain?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

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?

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?