Answer:
you have to add them together
At the end of the first year, the correct formula is this one:

The second year, we add r times the above amount, we get:

Iterating the process, we get the general formula of any number of years:
Answer:
200,000
Step-by-step explanation:
5 because they would most likely want a high amount of coins it's common sense. But if they were very strategic they'd probably also pick 3 but most of the time the value expected would be 5.