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

I shave every day, but my beard stays the same. What am I?

Asked by Neha on 12 Feb 2022


One of the leprechaun is missing if you see the two pictures attached to this question. Where did he go? When he comes back, do you know where has he been?

Leprechaun Puzzle

Asked by Neha on 26 Apr 2026

A woman who works in a sweet shop has a measurement of 32-26-36, is 5"4" tall, and wears size "6" shoes. What do you think she weighs?

Asked by Neha on 28 Apr 2026


Can you find the thief by just looking at the picture below?

Find The Thief

Asked by Neha on 20 Apr 2024

You need to complete the maze by entering from the entrance marked below in the figure near the yellow circle, bottom left and leaving from the exit point near the green circle, bottom middle.

Rule of Game: You can move only by exchanging green and yellow circles.

Cross the Gate

Asked by Neha on 21 Oct 2023

The more of this there is, the less you see. What is it?

Asked by Neha on 19 May 2022


Bea Smith, Vera Bennett, Franky Doyle and Doreen Anderson were in Wentworth Prison for murder. But their behaviour in the jails is appreciated by the warden and the warden decided to give all these 4 prisoners 11 cupcakes. They all like cupcakes and they had all cupcakes in no matter of time but they do not know how many cupcakes each individual had. Therefore Bea started the conversation Bea: "Hey T-Vera, did you have more cupcakes than I had ?"Vera: "I do not know girl, Hey Franky, did you have more cupcakes than I had ?".Franky: "I do not know"Doreen replied instantly: "I know how exactly how many cupcakes each of you had?" So can you tell how many cupcakes each of them had?

Asked by Neha on 21 Jul 2026

I have a clock(12-hour format) and both the needles of the clock overlap at 12:00.
After how much time, they will overlap again?

Asked by Neha on 06 Jan 2024

A time long back, there lived a king who ruled the great kingdom of Trojan House. As a part of the renovation of the kingdom to meet future security needs, he asked his chief architect to lay down a new play in a manner that all of his 10 castles are connected through five straight walls and each wall must connect four castles together. He also asked the architect that at least one of his castles should be protected with walls. The architect could not come up with any solution that served all of King's choices, but he suggested the best plan that you can see in the picture below. Can you find a better solution to serve the king's demand?

Castles in a line

Asked by Neha on 18 Sep 2023


You and your two friends are working in a multinational company. How can you three find out the average salary of you all without disclosing your own salary to the other two?

Asked by Neha on 26 Nov 2025

Hot Articles

Amazing Facts

Out of the Box

The phrase “thinking outside the box” was popularised from the solution to a topographical puzzle involving 9 dots in a box shape.