Final answer:
The real value of $100 in 10 years at a 0% annual inflation rate remains $100, as there would be no change in the purchasing power of the money.
Step-by-step explanation:
The question asks for the real value of $100 in 10 years at a 0% annual inflation rate if the money is kept under a mattress from the year 2019. When the inflation rate is 0%, it means that there is no change in the purchasing power of money over time. Thus, the real value of money remains the same. At a 0% inflation rate, there is no decrease or increase in the value of the currency due to inflation or deflation. Therefore, if you hide $100 under your mattress, after 10 years, the real value of that $100 would still be $100, assuming no other factors come into play, such as wear and tear or loss of the currency itself.
The real value of money refers to its purchasing power in terms of goods and services, accounting for inflation or deflation. It reflects the actual quantity of goods and services that a unit of currency can buy, providing a more accurate measure of an individual's or a nation's economic well-being.