Answer: there are 20 people who claimed to be neither CDO partisans nor ANC partisans.
Explanation:
To determine the number of people who are none of these two parties, we need to subtract the total number of people who claimed to be CDO partisans, ANC partisans, and those who claimed to be both from the total number of people surveyed.
Total surveyed people = 130
Number claiming to be CDO partisans = 80
Number claiming to be ANC partisans = 60
Number claiming to be both ANC and CDO = 30
To find the number of people who are none of these two parties, we can calculate it as follows:
None of these two parties = Total surveyed people - (CDO partisans + ANC partisans - Both ANC and CDO)
None of these two parties = 130 - (80 + 60 - 30)
None of these two parties = 130 - 110
None of these two parties = 20