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: a money lender lent rs . 1000 at 4 % per year and rs . 1400 at 5 % per year . the amount should be returned to him when the total interest comes to rs . 350 . find the number of years . 
Options: a ) 3.2 , b ) 3.75 , c ) 4 , d ) 4.25 , e ) 4.5
a

Problem: a , b and c enter into partnership . a invests some money at the beginning , b invests double the amount after 6 months , and c invests thrice the amount after 8 months . if the annual gain be rs . 21000 . a ' s share is ? 
Options: a ) 2999 , b ) 2778 , c ) 7000 , d ) 2889 , e ) 6612
c

Problem: a man sold 20 articles for $ 60 and gained 20 % . how many articles should he sell for $ 60 to incur a loss 20 % ? 
Options: a ) 30 , b ) 36 , c ) 40 , d ) 50 , e ) 48

a