Question

a survey asks: which online services have you used in the last month:

• twitter
• facebook
• have used both

the results show 24% of those surveyed have used twitter, 77% have used facebook, and 13% have used both.
what percent of the people surveyed used neither twitter nor facebook? %
question help: video

Explanation:

Step1: Calculate users of at least one service

$24\% + 77\% - 13\% = 88\%$

Step2: Calculate users of neither service

$100\% - 88\% = 12\%$

Answer:

12