a survey asks: which online services have you used in the last month:\n- twitter\n- facebook\n- have used…

a survey asks: which online services have you used in the last month:\n- twitter\n- facebook\n- have used both\nthe results show 24% of those surveyed have used twitter, 77% have used facebook, and 13% have used both.\nwhat percent of the people surveyed used neither twitter nor facebook? %\nquestion help: video
Answer
Explanation:
Step1: Calculate users of at least one service
$24% + 77% - 13% = 88%$
Step2: Calculate users of neither service
$100% - 88% = 12%$
Answer:
12