Video 1 in a series of official excerpts from the Kaplan GMAT program. In questions in which you’re asked to calculate an unspecified value, use the number 100. The instructor is Devin Landin – over 1300 students taught and counting.
httpvh://www.youtube.com/watch?v=02jCcEchlBs
Read the full article: Percents in the Answer Choices