Dave Green is senior tutor at examPAL, economist, political scientist and philosopher.

Algebra is the central subject we will face in the GMAT Quant section. It includes topics such as: integers, fractions, percents, ratio, decimals, expressions, equations, functions, positive and negative numbers, and more.

Approximately one third of all GMAT Quant questions, across all topics, are about Data Sufficiency. This is a special GMAT question format. What makes it unique is that it asks us to do something completely different from what we are used to. In Data Sufficiency, we are not asked to solve questions at all – but only to figure out if they CAN be solved!