AnkithaSrinivas
can somebody please explain?
Official Explanation
Get the Gist of the Information
You are given two lists of four book titles each; the fifth in each list is missing. The question asks you to find a book that would work on either list and to find a book that would work for neither list, given the publisher’s selection criteria for printed books and e-books. In other words, the question wants one answer that “could be true” for either list and one that “must be false” for both lists.
Answer the Questions
You don’t need to set up an equation to solve this problem, but you do need to use the GMAT Core Competency of Attention to the Right Detail as you consider the rules governing each set of books. Start by thinking about how to complete the list of printed books, which has only a single rule: there must be at least four Victorian titles. The list of printed books currently has only three Victorian titles, so you need a fourth. On Test Day, you would write, “Printed: need Victorian,” on your scratchwork.
The list of e-books is governed by two rules: there must be at least three works of detective fiction and at least four books by British authors. The list already includes two detective titles and three titles by British authors. It follows that you need a work of detective fiction by a British author to complete the list of e books. Your scratchwork might read, “E-books: need British detective fiction.”
A book permissible for either list must have all the qualities that the rules for both lists require. The title that “could be true” for either list, therefore, must be a work of British Victorian detective fiction. There are two such books available among the answer choices—those by Doyle and Collins. If you have paid Attention to the Right Details, however, you know that another rule from the question states that no author may be included more than twice on both lists combined. Doyle shows up on both lists already, so it follows that the Collins book, The Moonstone, is the only one that would satisfy the requirements of either list. Moreover, since Doyle has already appeared twice, he cannot appear again. So among the answer choices, the Doyle book is the “must be false” answer, the one that may not appear on either list.
Pay close attention to the column headings when filling in the answer choices. The correct answer for the first column (either printed or e-book) is The Moonstone by Collins, and the correct answer for the second column (neither printed nor e-book) is Doyle’s A Study in Scarlet.