Data Sufficiency is a little more complicated than problem solving. In a data sufficiency problem, you are given some information and a question and you have to figure out IF the problem can be solved based on that information.
Let’s look at an example with the same problem:
Jeb and Carla start at opposite ends of a 10 mile trail and start jogging towards each other at the same time. How many miles will Jeb have traveled when they cross each other?
(I) Jeb runs at a speed of 5 miles per hour
(II) Carla runs at a speed of 3 miles per
Your options for answers are:
A) (I) alone is sufficient, but (II) alone is not
B) (II) alone is sufficient, but (I) alone is not
C) Both together are sufficient, but neither alone is sufficient
D) Each statement is sufficient on its own
E) Both statements together are not sufficient
What the test means by sufficient is, that information can be used to solve the problem or answer the question. Pay attention to what the question asks, it could be as specific as the value (like this question), or it could be something more general, like: is X even? Depending on how specific the question is, you will need more or less information to solve it.
Important to note: once you know if you can solve it or not, don’t bother actually solving it. It’s a waste of time. Put in your answer and move on. Also, the order of the answers is the same every time so you should memorize it, so you can easily pick out which answer choice you are looking for.
So, how do you study for the Data Sufficiency section?
The information you will need for both quant sections include: fractions, decimals, percents, number problems, combinatorics, geometry, algebra and number properties. You will need to get a grasp on the various math rules within these topics through either a course, tutor or set of books. You will also need to practice your Data Sufficiency strategy with lots of practice questions. In order to work through DS questions efficiently, you need to work through them systematically.