What Data Sufficiency tests
Each Data Sufficiency question poses a question and two statements, (1) and (2). You do not answer the question; you decide whether the statements, alone or together, give enough information to answer it. The five choices never change: (1) alone, (2) alone, both together, each alone, or not even together. GMAC moved the format from Quant into Data Insights for GMAT Focus. Most questions still turn on algebra or number properties, but some test pure logic with no math at all.
How the GMAT Focus scores it
Each Data Sufficiency question counts once in the 20-question Data Insights section, which adapts to your answers and reports a score from 60 to 90. GMAC weights that score equally with Quant and Verbal in the 205–805 total.
Timing rule of thumb
Budget about 2 minutes; many take 90 seconds once you stop solving to the end. Test (1) alone, then (2) alone with (1) forgotten, and combine them only when each fails. Decide, record, and move on.
The two most common traps
1.Carrying (1) into (2)
After you work with statement (1), its facts linger while you judge (2). Then (2) looks sufficient when it is not, and you pick B instead of C, or D instead of A. Reset between statements.
2.Calling a definite No insufficient
On a yes/no question, a statement that proves the answer is always No is sufficient. A statement fails only when it allows both a Yes and a No.