An artist can imply deep space on a 2-dimensional surface by: a) overlapping forms
O b) making figures closer to the foreground appear larger
Oc) using linear perspective
O d
d) all of the above

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.  

answer:   2 1/4 pounds

explanation: 4 1/2 - 2 3/4