I love this question! It requires careful reading! There are multiple ways to get the right answer, so here are a couple! The sentence tells us the fraction of the questions he got RIGHT! To find this out you must multiply 3/5 by the total number of questions (3/5 x 15 = 9 correct questions). You then can subtract the 9 questions from the 15 total to find out the number that were INCORRECT/WRONG. 15 - 9 = 6 incorrect questions. Another strategy would be to find the fraction of questions Ethan missed, which is one minus the fraction he got RIGHT. 1 - 3/5 or 3/5 + ___ = 1 (5/5). He missed 2/5 of the questions, so you can multiply 2/5 by the total to get (2/5 x 15 = 6) 6 incorrect answers. Hope this helps!