Suppose that a survey of 100 advertisers in U.S. News, These Times, and World found the following.
6 advertised in all three
13 advertised in These Times and U.S. News
16 advertised in World and U.S. News
20 advertised in World and These Times
32 advertised in These Times
29 advertised in U.S. News
35 advertised in World

How many advertised in U.S. News or These Times?

A)48
B)96
C)11
D)17
E)18

Question

Suppose that a survey of 100 advertisers in U.S. News, These Times, and World found the following. ​
6 advertised in all three
13 advertised in These Times and U.S. News
16 advertised in World and U.S. News
20 advertised in World and These Times
32 advertised in These Times
29 advertised in U.S. News
35 advertised in World
​
How many advertised in U.S. News or These Times?
​
A)48
B)96
C)11
D)17
E)18

Quizplus · Accepted Answer

To find the number of advertisers in U.S. News or These Times, we add the advertisers in U.S. News (29) to those in These Times (32), and subtract those who advertised in both to avoid double counting. The number of advertisers in both U.S. News and These Times is given as 13, but this includes those who advertised in all three publications, which is 6. To avoid counting these thrice, we subtract them once from our total since we added them twice (once in U.S. News and once in These Times). So, the calculation is 29 + 32 - 13 = 48.

Suppose That a Survey of 100 Advertisers in U