Maths Logic

Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10




Similar Riddles

John has eleven friends. He has a bowl containing eleven apples. Now He wants to divide the eleven apples among his friends, in such a way that an apple should remain in his bowl.
How can He do it?

Asked by Neha on 05 Mar 2025


A man who was outside in the rain without an umbrella or hat didn’t get a single hair on his head wet. Why?

Asked by Neha on 27 Oct 2021

The picture shows the dice results in each couple of throws. If they are actually following a pattern, can you find out the missing one?

Next Dice Movement

Asked by Neha on 02 Dec 2023


Find out a multi-digit number that if multiplied by the number 9 or any of its multiplications products (i.e. 18, 27, 36, 45,..) will result in the multiplication factor repeated (n) number of times.

Asked by Neha on 08 Jan 2021

I am green and found in the forest and have needles instead of leaves. What am I?
Hint 1: It can be used for Christmas decorations.
Hint 2: I have a strong, scent that is used in air fresheners.

Asked by Neha on 29 Sep 2025

They do not possess flesh or feathers or scales or bone
But still, they are blessed with fingers and thumbs of their own.

Asked by Neha on 08 Nov 2023


All of Jacob's shoes are red except two.
All of Jacob's shoes are green except two.
All of Jacob's shoes are yellow except two.

How many shoes does Jacob have?

Asked by Neha on 15 Feb 2025

Do you know of a place where the wind blows south and then suddenly shifts direction towards the north?

Asked by Neha on 14 Sep 2025

John is asked to stand behind Jacob and Jacob is asked to stand behind John. Both of them feel confused about it and don't know what to do?

But it is quite possible, do you know how?

Asked by Neha on 28 Jan 2021


If a shopkeeper can only place the weights on one side of the common balance. For example, if he has weights 1 and 3 then he can measure 1, 3 and 4 only. Now the question is how many minimum weights and names of the weights you will need to measure all weights from 1 to 1000? This is a fairly simple problem and very easy to prove also.

Asked by Neha on 29 Oct 2023

Hot Articles

Amazing Facts

Word ladder puzzle

The word ladder puzzle was invented by Lewis Carroll, author of Alice’s Adventures in Wonderland.