The correct answer is D, 16 pages per minute. A unit rate is a ratio of something to one; in this case, the ratio is 16:1, or 16 pages to 1 minute. To get the unit rate for this problem, divide both numbers by 5 to get how many pages will be printed per 1 minute. 80/5 = 16, so the copier prints 16 pages in 1 minute. Answer choices A and B are not unit rates, and answer choice C is the incorrect unit rate.
