Question

Today, the price of a new cell phone is

$129. In 2000, the price of a similar cell
phone was $240. What is the percent of
change in the price of a cell phone from
2000 to today?

Answer 1

How to find the percentage you need to divide 129$ with 240$. You get 0,5375 and multiply that with 100 to get the percentage, wich is 53,75%.

How to know if this is correct is to think we know the price in 2000 and the percantage but not the price today. So then we take 240$ multiply with 0,5375, and get 129$. Now you know this is correct.