$.$ Sammy wants to take a sabbatical and he needs $$90,000$ to do so$.$ Today, he has $$25,000$ to invest at $8\%$ interest $($annual compounding$).$ In how many years will he have $$90,000?$

a$.$ Annual compounding? $\_\_\_\_\_\_\_\_\_\_\_\_($Ans: $16\mathrm{.}64$ years$)$

b$.$ If Sammy$$s bank pays interest on a quarterly compounding convention, how many years will it take? $\_\_\_\_\_\_\_\_\_\_\_\_\_($Ans: $16\mathrm{.}17$ years$)$

c$.$ Monthly compounding? $\_\_\_\_\_\_\_\_\_\_\_\_\_($Ans: $16\mathrm{.}06$ years$)$

d$.$ Daily compounding? $\_\_\_\_\_\_\_\_\_\_\_\_\_($Ans: $16\mathrm{.}01$ years$)$