Double Number Riddle

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?




Similar Math Riddles

In a basket of apples,
when counted in twos, there was one extra
when counted in threes, there were two extra when counted in fours, there were three extra
when counted in fives, there were four extra
when counted in sixes, there was five extra.

However, if the apples were counted in sevens, no extra apple was left. Can you calculate the minimum number of apples that were present in the basket?

Asked by Neha on 12 Sep 2023


If we add four times the age of John four years from now to five times his age five years from now we get ten times his current age.

How old will John be two years from now?

Asked by Neha on 19 Jan 2025

In a town, there are four houses located at different distances from each other. Following are the distances:

The third house is 60 meters apart from the first house.
The fourth house is 40 meters apart from the second house.
The third house is 10 meters nearer to the fourth house than it is to the second house.

Can you find out the distance between the fourth and the first house?

Asked by Neha on 14 Sep 2024


How can I get the answer 24 by only using the numbers 8,8,3,3?

You can use the main signs add, subtract multiply and divide.

Asked by Neha on 21 Jan 2026

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

Asked by Neha on 24 Sep 2023

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

Asked by Neha on 25 Sep 2021


A rain drop fell from one leaf to another leaf and lost 1/4th of its volume. It then fell to another leaf and lost 1/5th of the volume. It again fell on another leaf and lost 1/5th of the volume.



This process kept repeating till it fell on the last leaf losing 1/75th of its volume.



Can you calculate the total percentage of loss from the initial volume when the drop has fallen to the last leaf accurate up to two decimal places?

Asked by Neha on 16 Feb 2021

In case you were starting to feel confident, this one was meant for third graders in Vietnam. The answer is 66, but we don't blame you for scratching your head about how they got there.

Solve the Sudoku

Asked by Neha on 16 Feb 2022

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

Asked by Neha on 27 Aug 2021


Can you find the largest Three-digit number whose sum is 14 and whose square is less than 5,00,000?

Asked by Neha on 17 Mar 2026

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Word ladder puzzle

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