MathDB
Addition and Multiplication Swapping

Source:

March 15, 2010

Problem Statement

Given two 2's, "plus" can be changed to "times" without changing the result: 2+2=2·2. The solution with three numbers is easy too: 1+2+3=1·2·3. There are three answers for the five-number case. Which five numbers with this property has the largest sum?