product of 4 digts equals a no with last digit 7
Source: X May Olympiad (Olimpiada de Mayo) 2004 L1 P1
September 22, 2022
number theoryDigits
Problem Statement
Javier multiplies four digits, not necessarily different, and obtains a number ending in . Determine how much the sum of the four digits that Javier multiplies can be worth. Give all the possibilities.