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 shopkeeper sold an article at $ 100 with 10 % profit . then find its cost price ? 
Options: a ) $ 120 , b ) $ 100 , c ) $ 91 , d ) $ 72 , e ) $ 69
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 14 % ? 
Options: a ) 20 % , b ) 29 % , c ) 13 1 / 30 % , d ) 12 % , e ) 13 %
b

Problem: 63.2 is what percent of 867 ? 
Options: a ) 6.9 , b ) 8.99 , c ) 7.29 , d ) 7.98 , e ) 9.21

c