In 1907, the retrospective on the work of 19th century post-impressionist georges seurat influenced the development of cubism in a radical way through his painting titled, “sunday afternoon on the island of la grande jatte.” ? ?

yes that is correct and good

explanation:

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.