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 , 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 present value of a machine is $ 900 . its value depletiation rate is 25 % per annum then find the machine value before 2 years ? 
Options: a ) $ 1500 , b ) $ 1200 , c ) $ 1600 , d ) $ 1000 , e ) $ 1350
c

Problem: what profit percent is made by selling an article at a certain price , if by selling at 2 / 3 rd of that price , there would be a loss of 15 % ? 
Options: a ) 20 % , b ) 27.5 % , c ) 10 % , d ) 80 % , e ) 90 %

b