Making up numbers on GMAT data sufficiency questions containing variables is a great strategy, as you probably know by now. What you might not know is this nuanced aspect of this strategy that will help you better answer Yes/No GMAT data sufficiency questions and avoid common wrong answers. Dominate the GMAT founder Brett Ethridge explains this important GMAT tip and applies it to a sample data sufficiency question.
Source: GMAT prep
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