January/February 2009 CPE Puzzler

If Cat + Dog... If cat + dog = 7, and rat + mouse = 31, what does alligator + bird = ?

Answer: 3. In each equation the numerical position in the alphabet of the first letter of each word is used. Thus alligator + bird is 1 + 2, or 3 (the "a" in alligator is the 1st letter of the alphabet and "b" in bird is the 2nd).