To find the sum of an infinite geometric series having ratios with an absolute value less than one, use the formula, S=a11−r, where a1 is the first term and r is the common ratio.
Selection D is the equivalent form of the given expression.
_____
The nominal annual interest rate in this problem is 40%. If it were compounded half-yearly, the formula would be x(1.2)^(2t) or x(1.44)^t. Apparently, this problem is more concerned with the equivalent form of the expression than it is with half-yearly compounding.
I believe that 21 is d 27 over 17
I believe that 22 is d because 16 divided by 3.20 is 5
sorry if I am wrong
I hope this helps you
