Exactly six different essays will appear in a coming issue of a magazine. Three of the essays- G, I, and Jare by the writer K, and the other three essays-M, N, and P-are by the writer Y. Each essay will appear exactly once in the issue, and an essay must appear on each of the pages 3, 6, 9, 12, 15, and 18. The order in which the essays appear in the issue will be governed by the following conditions: The essays on pages 3, 9, and 15 must all be by the same writer. I must precede P. M must precede J. If I appears on page 12, which of the following is a complete and accurate list of all the essays any one of which could appear on page 9?

Explanation: The six pages are 3, 6, 9, 12, 15, 18. Essays by K: G, I, J. Essays by Y: M, N, P. Rules: (1) Pages 3, 9, 15 have the same writer. (2) I < P (I precedes P). (3) M < J (M precedes J). Given: **I is on page 12**. I is by writer K. Since page 12 is a K essay, all remaining K essays (G, J) must be in the pages for the other writer (Y), which is impossible (K essays must be with K essays, Y with Y). Thus, pages 3, 9, and 15 must be occupied by the Y writer's essays, {M, N, P} (since all K essays cannot be in {3, 9, 15} with I on 12). Pages {3, 9, 15} are for Y writers: {M, N, P}. The remaining pages {6, 12, 18} are for K writers: {G, I, J}. Given I is on 12. So, K essays on {6, 18} are {G, J}. Rule (2) is I < P. I is on 12. P must be on page 15 or 18. But P is a Y essay, so P must be on 3, 9, or 15. Since I is on 12, P must be after 12, so **P must be on 15**. (P cannot be on 18 as 18 is for K writers). Rule (3) is M < J. M is on 3 or 9. J is on 6 or 18. Since M is before J, M can be on 3 (J on 6 or 18) or M can be on 9 (J on 18). So the essays that could appear on page 9 are **M** and **N**. If M is on 9, N must be on 3. If N is on 9, M must be on 3. The list is M, N. (The explanation states G and J cannot be on page 9. Since I = 12, P cannot be on 9, leaving M and N).