Next comes a teensy bit of brute force.

We have three nationalities (German, Swede, and Dane) to put in three columns. Absent any further analysis, there are six ways to do so. However, we can use facts 2 and 3 to pare the list to just three ways.

For the heck of it, let's place the German first.

Suppose the German lives in house #2. Fact 3 tells us the Dane drinks tea so he cannot live in house #4. Thus the Swede is in house #4 and the Dane in #5.

Suppose the German lives in house #4. Fact 2 tells us the Swede keeps dogs as pets so he cannot live in house #2. Thus the Dane is in house #2 and the Swede in #5.

Suppose the German lives in house #5. Fact 3 tells us the Dane drinks tea so he cannot live in house #4. Thus the Dane is in house #2 and the Swede in #4.

We can also throw in fact 13 that the German smokes Prince cigars. All three possibilities are shown on the next page.