Final answer:
In financial mathematics, to calculate the rate of return, you subtract the initial purchase price from the selling price, divide by the purchase price, and multiply by 100. Denny's rate of return on the coin is 60 percent.
Step-by-step explanation:
The question "Denny buys a rare coin for $500 and sells the coin one year later for $800. Denny's rate of return is Multiple Choice- 300 percent. - 60 percent. - 80 percent. - 50 percent." involves calculating the percentage increase from the original price to the selling price, which is a common problem in financial mathematics.
To find the rate of return, we calculate the percentage increase by subtracting the purchase price from the selling price, dividing this by the purchase price, and then multiplying by 100 to convert it into a percentage. This gives:
(Selling Price - Purchase Price) / Purchase Price * 100
So, Denny's rate of return would be:
($800 - $500) / $500 * 100
Which simplifies to:
$300 / $500 * 100
And results in a rate of return of 60 percent.