Table: Participants in a regional review session — Region I 120, Region II 80, Region III 200, NCR 400. How many participants were there in all?
Correct answer: D. 800
Add all four regions: 120 + 80 + 200 + 400 = 800. Grouping 120 + 80 = 200 and 200 + 400 = 600 makes the total quick. Always total the table before working out shares.
easy