Postage Stamps
  • The country of Zin�s monetary unit is the grog. The nation's postal service sells only 5 grog and 11 grog stamps. Using Zin stamps, a person can make exact postage of 21 grogs with two 5-grog stamps and one 11-grog stamp. However, one cannot make exact postage of 23 grogs by using any combination of only 5-grog stamps and 11-grog stamps. What is the greatest value in grogs that one cannot use for postage in the country of Zin?

Answer:    
  Please enter a numerical answer
(ex. 1000 or 2.033) and click GO.		    

Contest problems and answers provided by:

David Rock
rock_david@colstate.edu
Columbus State University

Doug Brumbaugh
brumbad@pegasus.cc.ucf.edu
University of Central Florida