Of 320 consumers polled, some purchase Blu-ray movies, some only purchase movies on DVD, and some do both. If 300 people polled purchase Blu-ray discs and 280 purchase DVDs and Blu-ray discs, how many people only buy DVDs?
If you put together a Venn Diagram it will help you to see the solution you are looking for : )
To find the number of people who only buy DVDs, we need to subtract the number of people who purchase both DVDs and Blu-ray discs from the total number of people who purchase DVDs.
Let's break down the information given:
- 320 consumers were polled.
- 300 people purchased Blu-ray discs.
- 280 people purchased DVDs and Blu-ray discs.
To find the number of people who only buy DVDs, we can use the concept of sets and set operations. We know that the total number of people who purchased DVDs is 280. Out of these 280 people, some also purchased Blu-ray discs, meaning they belong to the overlapping area between the DVD and Blu-ray sets.
To find the number of people who only bought DVDs (i.e., those who belong exclusively to the DVD set), we need to subtract the number of people who purchased both DVDs and Blu-ray discs from the total number of people who purchased DVDs.
Let's calculate it:
Total number of people who purchased DVDs = 280
Number of people who purchased both DVDs and Blu-ray discs = 280
Number of people who only buy DVDs = Total number of people who purchased DVDs - Number of people who purchased both DVDs and Blu-ray discs
= 280 - 280
= 0
Hence, based on the given data, there are 0 people who only buy DVDs.