Well, the test is arranged so that the letter for the country will allways be D, since any number between 1 and 10 that is multiplied by 9 will have the product's component digits always add up to 9 so after subtracting the 5 you will be left with 4 = 'D' And since there are only 3 countries, I think, that begin with 'D' --Denmark, Djibouti and Dominican Republic-- and since Denmark is the most commonly remembered you are inclined to think of this. Uguel