Question 34609
Formula for Sum of n terms 
S(n)=a[1-r^n]/(1-r)
S(4)=1[1-(1/2)^4]/(1-(1/2)] = 1.8750...
S(12)= 1[1-(1/2)^12]/[1-(1/2)]=1.9999...
Getting close and closer to "2".
Cheers,
Stan H.