MathDB

7143 somewhere in decimal expansion => huge denominator

Source: Bundeswettbewerb Mathematik 2015 - Round 2 - #2

September 4, 2015

number theoryFractiondecimal representation

Problem Statement

In the decimal expansion of a fraction

\frac{m}{n}

with positive integers

m

and

n

you can find a string of numbers

7143

after the comma. Show

n>1250

.
Example: I mean something like

0.7143