MathDB
simplify be reducing gives correct (V Soros Olympiad 1998-99 Round 3 9.2)

Source:

May 25, 2024
algebranumber theory

Problem Statement

As evidence that the correct answer does not mean the correctness of the proof, the teacher cited next example. Let's take the fraction 1995\frac{19}{95}. After crossing out 99 in the numerator and denominator (“reduction” by 99), we get 15\frac{1}{5} which is the correct answer. In the same way, a fraction 19999995\frac{1999}{9995} can be “reduced” by three nines (cross out 999999 in the numerator and denominator). Is it possible that as a result of such a “reduction” we also get the correct answer, equal to 13\frac13 ? (We consider fractions of the form 1aa3\frac{1a}{a3}. Here, with the letter aa we denote several numbers that follow in the same order in the numerator after 11, and in the denominator before 33. “Reduce” by aa.)