Question 1085094
P=Poe^rt for continuous compounding, where r=0.027 and t=8.  Note, the rule of 72 would say 72/2.7 is the doubling time, which is about 27 years.
=11000*e^(.027*8)=10000*e^.216=$13652.13 This is as expected not even close to doubling.  
20000=11000e(.027*t)
1.818=e^(.027t)
ln both sides, without rounding, then divide by 0.027
0.5978=0.027*t
t=22.14 years