In a USA TODAY/Gallup Poll, respondents favored Barack Obama over Mitt Romney in terms of likability, 60% to 30% (Los Angeles Times, July 28, 2012). The following bar chart summarizes the responses:
Obama: 0.60
Romney: 0.30
What percentage of respondents favored neither Obama nor Romney in terms of likability?
b. Suppose this survey was based on 500 respondents. How many respondents favored Obama over Romney?