Data Sufficiency Cheat Sheet

Data Sufficiency Cheat Sheet

Quick Revision

A data sufficiency question gives a question and two statements. You must decide whether the statements give enough information to answer — without actually solving the problem.

1. The Golden Rule

Judge sufficiency, do NOT find the final answer.
A statement is sufficient if it leads to exactly one answer.

2. The Five Options

(a) Statement I alone is sufficient, II alone is not
(b) Statement II alone is sufficient, I alone is not
(c) Each statement alone is sufficient
(d) Both together are needed; neither alone is enough
(e) Both together are still not sufficient

3. The Method

1. Test statement I alone — ignore II completely.
2. Test statement II alone — ignore I completely.
3. Only if neither alone works, test both together.

4. Worked Example

Question: What is the value of x?

• I. x + 5 = 12 → gives x = 7 on its own → sufficient.
• II. x is a positive even number → many values → not sufficient.

Statement I alone is sufficient, II alone is not → the answer is (a).

5. Exam Quick Tips

• Never waste time computing the whole answer — you only need enough or not enough.
• Test each statement in isolation before combining them.
• A statement giving more than one possible value is not sufficient.

Keep revising with the rest of the Reasoning section:

• All Reasoning topics
• Decision Making Cheat Sheet
• Logical Sequence Cheat Sheet

How this was made: Drafted with AI assistance; spot-checked by the editor on 31 October 2026.