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

How much will a 38° angle measure when looked at under a microscope that magnifies ten times?

Asked by Neha on 17 May 2021


A man wants to cross the pit of fire which is 25 feet in length and he has 2 planks(fire resistant) 19 feet in length. How can he cross the pit of fire alive?

Asked by Neha on 02 Oct 2025

Do you know who was buried in John's tomb?

Asked by Neha on 27 Feb 2026


How many bricks does it take to complete a building that is 15 feet wide, 30 feet deep, and 12 feet tall made of brick?

Asked by Neha on 23 Feb 2024

When monkey rotate the gear, which mark will be hit 1 or 2 ?

Monkey Gear riddle

Asked by Neha on 30 Apr 2021

Sally lives in a place where six months of the year is mild summer and the temperature drops significantly the other six months. She owns a lake where there is a small island. She wants to build a house on the island and needs to get materials there. She doesn’t have a boat, plane, or anything to transport them to the island. How does Sally solve this problem?

Asked by Neha on 09 Jun 2025


I am working in a bus company. The company recently went under expansion and therefore there was not enough room for all the buses. As a result, twelve buses had to be stored outside.

If the company decides to expand the garage space by forty percent, enough space to accommodate the current buses will be created leaving enough space for twelve more buses if the need arises in future.

Can you calculate the number of buses that the company owns at present?

Asked by Neha on 18 Dec 2020

Kareena is older than Bipasha. Bipasha is younger than Karishma and younger than Katrina. Katrina is older than Kareena and Alonso, who are older than Karishma.If Alonso and Kareena are twins, who's oldest?

Asked by Neha on 06 Jun 2026

As we know that white starts the game of chess. Can you find the scenario shown in the picture below is possible when all the white pieces are at the original place while the black pawn is not as in the below picture?

Chess Game Trick

Asked by Neha on 04 Sep 2023


In a football game, Christina defeated Teresa by 2 - 0 but no man from either side scored. How can this be possible?

Asked by Neha on 08 Jan 2025

Hot Articles

Amazing Facts

Rubik’s Cube

The inventor of the Rubik’s Cube didn’t realize he’d built a puzzle until he scrambled it the first time and tried to restore it.