In Data Sufficiency you do not solve the problem. You decide whether the information given is enough to solve it. The five answer choices are always the same: statement (1) alone is enough, (2) alone is enough, both together are enough, each alone is enough, or not even both together.
When unsure, many people pick “both statements together”. It feels safe because it never asks you to commit to either statement on its own.
What that habit costs
Many students pick “both together” whenever they are unsure, and it is often wrong. On many of those questions, a single statement was already enough.
An example
Is x > 2? (1) x² > 4. (2) x³ > 8.
Statement (1) allows x = 3, but also x = −3, so it is not enough alone. Statement (2) means x > 2, exactly what was asked. So (2) alone is enough, and the answer is B, not C.
The order of work
- Test statement (1) on its own. Write down: enough, or not enough.
- Forget (1). Test statement (2) on its own. Write it down.
- Only if neither is enough alone, combine them.
Writing the verdict down for each statement is what breaks the habit. It makes you decide before you are allowed to combine.
ChatGMAT spots habits like this in your own mocks and gives you short sets to break them.