## Teaser 2565: Red and black

**From The Sunday Times, 20th November 2011** [link]

I have taken 10 cards and written a different digit on each one. Some of the cards are red and the rest are black. I have placed some of the red cards in a row to form a long number. Then I have moved the last card to the front to give me a larger number. In fact this larger number divided by the original one equals a digit on one of the black cards.

What was the original number?

[teaser2565]

## Jim Randell 3:53 pm

on11 February 2019 Permalink |This puzzle is similar

Enigma 1036.Here is a Python program that solves it using a similar analysis.

Run:[ @replit ]Solution:The original number is230769.So we have:

If we allow leading zeros there is a further solution:

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## Frits 11:42 am

on29 October 2020 Permalink |@Jim,

Is the phrase “some of the red cards” the reason why “n” cannot be 9?

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