... five possible answer choices. You are required to select the best answer. Ability Tested Problem Solving questions test your ability to solve mathematical problems in- volving arithmetic, algebra, ... so D is the correct answer. Working from the answers is a valuable technique. 7. What is the greatest common factor of the numbers 18, 24, and 30? A. 2 B. 3 C. 4 D. 6 E. 12 The largest number ... answers, but here you should start with the largest answer choice, because you’re looking for the greatest common factor. The correct answer is D. If you don’t immediately recognize a method or formula...