Along, curving line that leads a viewer's eye around a canvas is an example of which principle of design?
a. form
b. movement
c. rhythm
d. shape

including the octave, the answer would 8 notes in a major scale with one note being played twice. ex) c major scale includes: c, d, e, f, g, a, b, c

notice that c is played twice

however, if you were to ask me how many different notes are in a major scale- the answer would be 7.  

the longest time is 123 years