# Versatile Coins

by Dan Velleman and Istvan Szalkai

Year of Award: 1994

Publication Information: The American Mathematical Monthly, vol. 100, 1993, pp. 26-33

Summary: This article discusses the problem of one probability $p$ simulating a second probability $q$, meaning that with a coin that comes up heads with probability $p$, we can simulate in a finite number of tosses the behavior of a coin that comes up heads with probability $q$. The particular question throughout is to characterize the sets of probabilities for which there is a single coin that simulates every element in the set.