Here is a set of free short videos for stepwise preparation of Data Sufficiency on GMAT. For a more detailed treatment of the topic, you may want to opt for our GMAT online course or our GMAT test series of 15 mock tests.
Approach for DS Questions
Properties of a "Sufficient" DS Statement on GMAT
1 of 5 - Common Mistakes in Data Sufficiency
2 of 5 - Common Mistakes in Data Sufficiency
3 of 5 - Common Mistakes in Data Sufficiency
4 of 5 - Common Mistakes in Data Sufficiency
5 of 5 - Common Mistakes in Data Sufficiency
Even and Odd - 3 Amazing DS Examples on GMAT