Answer:
1/2
Step-by-step explanation:
7/10 - 2/10 = 5/10
5/10 simplifies to 1/2 by dividing numerator and denominator by 5.
320
You add all the numbers together then divide by how many numbers there was. In this case all the numbers added to 6405. You divide by 20 because there were 20 numbers. This will get you to 320.25. The closest answer choice would be 320
If we were to put this in terms of a venn diagram, we would have 360 owning only brand X, 500 owning only brand Y, and 80 in between, owning both. Therefore, 80 out of the 580 owners of brand Y may have X as well, which we put into fraction form 80/580, and reduce to 4/29.