Posted by azmeerahim on .
Given a geometric progression:
0.05, 0.2, 0.8, ... Find the sum from the 5th term to the 8th term?

Math 
Steve,
That would be S8  S4
Since r = 4
.05(4^81)  .05(4^41) = 3264 
Math 
azmeerahim,
a=0.05
r=4
S8=0.05(4^81)/3=1092.25
S4=0.05(4^41)/3=4.25
Sum from 5th term to 8th term is
S8S4=1088