I'm guessing S^20 is actually referring to the 20th partial sum
, with
in the arithmetic case, and
in the geometric case.
(a) Combining like terms, we have
and invoking the formula
we end up with
(b) Multiply
by 1.1, then subtract this from
:
Answer:
(-2.2,-3)
Step-by-step explanation:
111.28 1/8=0.125 0.125*890.20=111.275 money can only have 2 decimals so round up and $111.28 is your answer.