AIME 1991 Problem 5

Paper
Answer

Given a rational number, write it as a fraction in lowest terms and calculate the product of the resulting numerator and denominator. For how many rational numbers between $0$ and $1$ will $20_{}^{}!$ be the resulting product?

Dataset text AIME 1983 to 2026. Quoted with source.

Show the answer

128

Solutions

No solution is on olymmath yet. Official and human solutions come first when they arrive. AI solutions come after them, with a label.

Add a solution

Locator aime/1991/p5 · Tag V7TVTE4DT5 · Edit this page on GitHub · Keys: j next, k previous