Assuming annual compounding, find how long it would take for the general level of prices to double at the following annual inflation rates. a$.\backslash (3\backslash \%\backslash )$ b$.\backslash (5\backslash \%\backslash )$ c$.\backslash (9\backslash \%\backslash )$ d$.$ Check your answers using the Rule of $70$ or the Rule of $72,$ whichever applies. a$.$ It will take approximately years. $($Round to one decimal place as needed.$)$