In this task, you need to answer the given multiple-choice question on the gain. Gain is the value by which to multiply the input. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.
--------
Question: Problem: find the compound interest on $ 20000 in 2 years at 4 % per annum , the interest being compounded half - yearly ?
Options: a ) $ 645.56 , b ) $ 1648.64 , c ) $ 954.26 , d ) $ 745.69 , e ) $ 1020.45

Answer: b

Question: Problem: one night 17 percent of the female officers on a police force were on duty . if 170 police officers were on duty that night and half of these were female officers , how many female officers were on the police force ?
Options: a ) 400 , b ) 420 , c ) 450 , d ) 480 , e ) 500

Answer: e

Question: Problem: at what rate percent per annum will a sum of money double in 16 years ?
Options: a ) 10.6 % , b ) 3.65 % , c ) 6.25 % , d ) 8.32 % , e ) 11 %

Answer:
c