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'.

Problem: the difference between simple and compound interest on rs . 1600 for one year at 10 % per annum reckoned half - yearly is ? 
Options: a ) 8 , b ) 3 , c ) 9 , d ) 4 , e ) 2
d

Problem: in order to obtain an income of rs . 1000 from 50 % stock at rs . 500 , one must make an investment of 
Options: a ) rs . 17000 , b ) rs . 16050 , c ) rs . 15400 , d ) rs . 10000 , e ) rs . 10500
d

Problem: what is the compound interest on rs : 30,000 for 4 months at the rate of 5 % per annum 
Options: a ) 501.13 , b ) 502.13 , c ) 503.13 , d ) 504.13 , e ) 505.13

c