Hi rkhicha,

This is a weighted average GMATPrep question. We want to know whether at least 10% of older ppl are employed. Statement 1 gives us no employment data. Statement 2 tells us that 10% of older women and 20% of older men are employed. The % of the entire older population that is employed will be a weighted avg of the older men and the older women. Thus the % of the entire older population that is employed will be somewhere between 10% and 20%. It is guaranteed that at least 10% of this population is employed. Statement 2 is sufficient and B is the correct answer.

A more detailed explanation and video solution are available at GMATPrep Question 1265. To practice similar questions, set topic='Weighted Averages and Sets & Groups' and difficulty='600-700 & 700+' in the Drill Generator.

Hope that helps,
-Patrick