The informal answer to your question is "clipboard". However, there isn't such a thing as the "clipboard". The people who came up with the idea of the clipboard use that nomenclature to describe the location in memory where that copied data resides. So the formal answer to your question is memory or RAM.
Answer:random
Explanation:
A random method returns a number between zero and one.
B. true
RAM (Random Access Memory) is volatile because if power is lost, so is your memory.
Answer:
previousAddition instance variable
Explanation:
In order to accomplish this you would need to add a previousAddition instance variable. In this variable you would need to save the amount that was added at the end of the process. Therefore, if a mistake were to occur you can simply call the previousAddition variable which would have that amount and subtract it from the total. This would quickly reverse the mistake, and can be easily called from the undo() method.
