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PROJECT EULER · #0243

Resilience

Statement only · SolvedOriginal problem ↗

A positive fraction whose numerator is less than its denominator is called a proper fraction.
For any denominator, d, there will be d1 proper fractions; for example, with d=12:
1/12,2/12,3/12,4/12,5/12,6/12,7/12,8/12,9/12,10/12,11/12.

We shall call a fraction that cannot be cancelled down a resilient fraction.
Furthermore we shall define the resilience of a denominator, R(d), to be the ratio of its proper fractions that are resilient; for example, R(12)=4/11.
In fact, d=12 is the smallest denominator having a resilience R(d)<4/10.

Find the smallest denominator d, having a resilience R(d)<15499/94744.

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