Himwood has 1200 ft2 of roof in his home in pittsburgh, pa (hdd = 6,000). he is considering upgrading the insulation from r-16 to r-22. the estimate from the contractor was $520. his home is heated with natural gas. last year, the average price he paid for natural gas was $13.3/mcf. assuming an afue of 82.2%, how long will it take himwood to recover his investment?

the answer is counterpoint.

counterpoint definition: "the art or technique of playing a melody or melodies in conjunction with another, according to fixed rules."

counterpoint is present in a lot of baroque music- such as bach (notably his wtc prelude and fugues) and scarlatti, but can also be found in music by mozart, beethoven. it can even be found in music as modern as john williams!