Calculate the amount that an investor needs to be invest to earn $1005 in interest in 12 months if the investor plans to invest x dollars in a savings account that pays interest at an annual rate of 11% compounded semi-annually?
Options:
A) 8000
B) 8100
C) 8900
D) 8600
E) 8400

Rationale: "the approach is substitution , our interest requirement is $ 1005 after 12 months , 2 compounding period . calculate the compound interest on each option and find out the one that yields 460 in 12 months 8900 yielded $ 1005 using the formula a = p ( 1 + r / n ) nt hence answer is c"
Answer: C