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

1 rabbit saw 9 elephants while going to the river. Every elephant saw 3 monkeys going toward the river. Each monkey had 1 parrot in each hand. How many animals are going towards the river?

Asked by Neha on 30 Aug 2025


John, a 5-year-old boy, was really fond of the chocolates. He asked his Mother to give him some money to buy his favourite chocolates. His Mother gave him $45. He went to the shopkeeper and asked, "How much is one chocolate for?". The shopkeeper said $3 for one chocolate. Also, if you give me the wrappers of three chocolates, I will give you one for the exchange.
In total, how much chocolate could John eat?

Asked by Neha on 02 Feb 2026

The pound is not a finish.

We are sharing a few instructions below, which you have to use in any suitable order to modify the above sentence such that the end sentence is a scientific fact.

- Eliminate a letter and supplement another in its place.
- Take away one word.
- Remove one letter from one word.
- Get rid of two letters from one word.
- Swap a word with its antonym.

Asked by Neha on 03 May 2025


Two friends were stuck in a cottage. They had nothing to do and thus they started playing cards. Suddenly the power went off and Friend 1 inverted the position of 15 cards in the normal deck of 52 cards and shuffled it. Now he asked Friend 2 to divide the cards into two piles (need not be equal) with equal number of cards facing up. The room was quite dark and Friend 2 could not see the cards. He thinks for a while and then divides the cards in two piles.

On checking, the count of cards facing up is same in both the piles. How could Friend 2 have done it ?

Game with Cards

Asked by Neha on 02 Mar 2021

What is the word or phrase below?
R | E | A | D

Asked by Neha on 28 Jul 2024

John said, "If yesterday was tomorrow, today would be Friday."

When did John make this statement?

Asked by Neha on 09 Apr 2025


What time is it when an elephant sits on a fence?

Asked by Neha on 10 Jul 2025

I have Rs.50 and I spend it in the way as below.

Fund and Spends

Asked by Neha on 01 Oct 2023

1. What does:
TIM JOB
represent?

2. What does:
MO_ _
represent?

Asked by Neha on 21 Feb 2025


Count the number of balls in picture below:


Count The Balls

Asked by Neha on 21 May 2021

Hot Articles

Amazing Facts

Challenging

There is a cryptic organization called Cicada 3301 that posts challenging puzzles online, possibly to recruit codebreakers and linguists.