There is a list of 7 distinct positive integers less than 10. One can not deduce whether their sum is a multiple of 3 from their product. What is their product?
Sunday, August 21, 2011
Please email your solutions to firstname.lastname@example.org.
This is an original cotpi puzzle inspired by:
- Andreescu, Titu; Andrica, Dorin; Feng, Zuming. 104 Number Theory Problems: From the Training of the USA IMO Team. Boston: Birkhäuser, 2007. p. 4. Example 1.4.
The following is a list of resources on related topics:
- Pal, Susam. "Solving the Impossible Puzzle." Susam Pal. 21 Mar. 2010. 9 Sep. 2011 <http://susam.in/blog/solving-impossible-puzzle/>.
- Weisstein, Eric W. "Modular Arithmetic." Wolfram MathWorld. 29 Aug. 2011. Wolfram Research. 9 Sep. 2011 <http://mathworld.wolfram.com/ModularArithmetic.html>.