Roundoff Riddle

Find a 9-digit number, which you will gradually round off starting with units, then tenth, hundred etc., until you get to the last numeral, which you do not round off. The rounding alternates (up, down, up ...). After rounding off 8 times, the final number is 500000000. The original number is commensurable by 6 and 7, all the numbers from 1 to 9 are used, and after rounding four times the sum of the not-rounded numerals equals 24.




Similar Riddles

How can you take 2 from 5 and leave 4?

Asked by Neha on 03 Apr 2022


Solve the equation by replacing the alphabet with numbers.

MOM + MOM + NO = BOOK=

Asked by Neha on 06 Aug 2023

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?

Asked by Neha on 30 May 2024


Krish is 45 years old and his mother Crishtina is 73 years old.

Can you find out how many years ago, his mother was three times his age?

Asked by Neha on 18 Mar 2024

The product of three consecutive numbers is 7980.
Then the sum of these consecutive numbers would be?

Asked by Neha on 23 Apr 2025

What do you get if you add 2 to 100 four times?

Tricky Maths

Asked by Neha on 24 Jun 2024


Can you find a seven digit number which describes itself. The first digit is the number of zeros in the number. The second digit is the number of ones in the number, etc. For example, in the number 21200, there are 2 zeros, 1 one, 2 twos, 0 threes and 0 fours.

Asked by Neha on 23 Jul 2021

There is a basket full of hats. Three are white and two are black. Three men, Tom, Tim, and Jim, each take a hat out of the basket and put it on their heads without seeing the hat they selected or the hats the other men selected. The men arrange themselves so Tom can see Tim and Jim’s hats, Tim can see Jim’s hat, and Jim can’t see anyone’s hat. Tom is asked what color his hat is and he says he doesn’t know. Tim is asked the same question, and he also doesn’t know. Finally, Jim is asked the question, and he does know. What colour is his hat?

Asked by Neha on 06 Jun 2025

A man is found hanging dead from the ceiling of a room. The room’s dimensions are 15 x 15 x 15. The man is only 6ft tall and the rope was only 2ft long. There are no windows and only one door to the room. The door is bolted shut from the inside, and a puddle of water is under the man. How did he kill himself?

Asked by Neha on 03 Sep 2025


There is a barrel with no lid and some wine in it. 'This barrel of wine is more than half full,' said Curly. 'No it's not,' says Mo. 'It's less than half full.' Without any measuring implements and without removing any wine from the barrel, how can they easily determine who is correct?

Asked by Neha on 05 May 2023

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.