Keep in mind that we have 6 spots and 5 items for export. All 5 items must be exported by at least 1 country. So, how many can be exported by more than one country? Just 1.
For example:
S S O R T W fills up all six spots. Only S is duplicated.
S S O O R T W means that one variable would be left out. Two sets of duplicates is not possible. Make sure you pay attention to your quantities.
19 tells us that Nation X exports soybeans and tea. What rules come into play?
We know that Nation Y must also export soybeans. We know the following:
X: S T Y: S _ Z: _ _
There are two ways to make the deduction that Z gets rice. First, if Y were to get rice, then X and Z both get tea, according to rule three. This leaves us with two sets of duplicates, S and T, which is not possible. This means that Z is the only available spot for rice.
Second, remember that wheat and oranges must be separated.
X: S T Y: S W/O Z: W/O R
The second export for Y must be reserved for either wheat or oranges. This leaves Z as the only country that could export rice.
