How can you calculate the number of households subscribing to only one newspaper if 39 households subscribe to at least one of the three newspapers?

The correct method to calculate the number of households subscribing to only one newspaper is to total the subscriptions and remove any overlaps. This approach involves using set theory principles to assess the relationships between the subscriptions to the newspapers.

First, identify the total number of subscriptions to each newspaper, then account for households that may subscribe to more than one newspaper, which is referred to as overlaps. This requires data on how many households subscribe to each individual newspaper, as well as information about households that subscribe to combinations of the newspapers.

By applying these principles effectively, you can accurately determine how many households are subscribed exclusively to one newspaper. This approach is comprehensive and ensures that you account for all potential overlaps, leading to a precise calculation of the desired number.

The other methods, such as dividing or multiplying totals, do not accurately account for the overlapping subscriptions, which is crucial for determining the count of unique subscriptions. Thus, simply totaling subscriptions will lead to incorrect conclusions unless the overlaps are specifically addressed and removed to find the number of households subscribed to only one paper.