Facts: norwegian(1) norw left of blue: blue(2) center: milk milk(3) green left of white => neither one is (2) green=coffee => green not middle => green(4) white(5) => coffee(4) Brit = red => not(1), not(2), not(4), not(5) red(3) Brit(3) => 4 colors known, =>yellow(1) [7]: dunhill(1) [11]: horses neighbor dunhill horses(2) [12]: winfield = beer => not 1 (=dunhill), not 3 (=milk), not 4 (=coffee) => 2 or 5 [3]: dane=tea => not 1 (=norw), not 3 (=milk),not 4 (=coffee) => 2 or 5 => 4 drinks known, => water(1). [15]: marlboro neighbor water marlboro(2) => from above: winfield=beer must be 5: winfield(5) beer(5) and dane=tea must be 2: dane(2) tea(2) => rothmans and pallmall must be in houses 3 and 4 [13]: german=rothmans => as Brit(3): german(4) rothmans(4) pallmall(3) [6]: pallmall=birds birds(3) [10]: marlboro neighbor cats => cats in 1 or 3 => cats(1) [2] swede=dogs: not 1 (=norw), not 2 (=dane), not 3 (=birds), not 4 (=german) swede(5) dogs(5) (could have been done immediately after deriving german(4) from nationality) => all animals known except fish => fish(4).