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

A donkey is behind another donkey
I'm behind that second donkey
But there is a whole nation behind me

It is a murder you can describe in a word.

Asked by Neha on 16 Nov 2025


What type of tree can I carry in my hand?

Asked by Neha on 04 Apr 2025

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

Asked by Neha on 18 Jan 2025


A farmer went to a market and bought a wolf, a goat, and a cabbage. On his way home, the farmer came to the bank of a river and rented a boat. But crossing the river by boat, the farmer could carry only himself and a single one of his purchases: the wolf, the goat, or the cabbage. If left unattended together, the wolf would eat the goat, or the goat would eat the cabbage. The farmer’s challenge was to carry himself and his purchases to the far bank of the river, leaving each purchase intact. How did he do it?

Asked by Neha on 21 May 2025

A father's child, a mother's child, yet no one's son.

Who am I?

Asked by Neha on 21 Mar 2022

There is a circular car race track of 10km. There are two cars, Car A and Car B. And they are at the exact opposite end to each other. At Time T(0), Both cars move toward each other at a constant speed of 100 m/seconds. As we know both cars are at the same speed they will always be the exact opposite to each other.
Note, at the center, there is a bug which starts flying towards Car A at time T(0). When the bug reaches car B, it turns back and starts moving towards the car A. The speed of bug is 1m/second. After 5 hours all three stop moving.
What is the total distance covered by the bug?

Asked by Neha on 03 Aug 2023


John drives to his office at 20km/hr. After reaching the office, he realizes that today is a holiday. He went back at an average speed of 30km/hr. Discounting the time spent in the stoppage what was the average speed of his journey?

Asked by Neha on 21 Apr 2025

A boy was at a carnival and went to a booth where a man said to the boy, "If I write your exact weight on this piece of paper then you have to give me $50, but if I cannot, I will pay you $50." The boy looked around and saw no scale so he agrees, thinking no matter what the carny writes he'll just say he weighs more or less. In the end the boy ended up paying the man $50. How did the man win the bet?

Asked by Neha on 26 Jan 2023

Can you solve the below tricky visual equation?

Visual Equation

Asked by Neha on 29 Jun 2024


Can you name some countries which do not have the alphabet 'A' in them?

Asked by Neha on 17 Aug 2024

Hot Articles

Amazing Facts

Gambling

In Canada, a mathematical puzzle must be solved in order to win the lottery to classify it as a “game of skill” not gambling.