Which infinite geometric series can you NOT find the sum? A) 96, 24, 6, 1.5, 0.375,...
B) 81, 72.9, 65.61, 59.049,...
C) 127, 152.4, 182.88, 219.456,...
D) 154, 53.9, 18.865, 6.60275,...

C) 127, 152.4, 182.88, 219.456,...

Step-by-step explanation:

You can only find the sum of an infinite geometric sequence if it converges.

One criterion to see if the series converges is if:

aₙ < aₙ₋₁

This means that, as n increases, the value of the terms decreases.

This means that as n tends to infinity, aₙ tends to zero.

Then we only can find the sum of those series where the terms are decreasing.

in A, B and D the terms are decreasing, then we can find the sum of those 3 series.

Now in the case of C, the terms are increasing, then we can not find the sum of that series.