Consider a hypothetical economy that grows at a rate of 4% per year. Approximately how many years will it take for this economy to double in size?
Note: the size of an economy is its real GDP.
Hint: to solve this problem, you first want to set up an equation that links the future size of the economy to its current size and the growth rate.
Honestly I have no idea where to start. If anyone has any clue as to solve this I would greatly appreciate some help!