Justin has written 5 novels with an average length of 450 pages. If his sixth novel is 750 pages long, what is the average length of all 6 novels?

A 500 pages

B 550 pages

C 600 pages

D 650 pages

Option A: 500 pages

Explanation:

1. Number of pages of the first 5 novels

Average = [Number of pages] / [number of novels]

450 pages / novel = Number of pages / 5 novels

Number of pages = 5 novels * 450 pages / novel = 2,250 pages

2. Average length of all 6 novels

Average = [Number of pages] / [number of novels]

Number of pages of 6 novels = 2,250 pages + 750 pages = 3,000 pages

Average = 3,000 pages / 6 novels = 500 pages / novel