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 shop owner professes to sell his articles at certain cost price but he uses false weights with which he cheats by 30 % while buying and by 10 % while selling . what is his percentage profit ? 
Options: a ) 10.22 % , b ) 20.22 % , c ) 21.22 % , d ) 30 % , e ) ca n ' t be calculated
d

Problem: you hold some gold in a vault as an investment . over the past year the price of gold increases by 60 % . in order to keep your gold in the vault , you must pay 10 % of the total value of the gold per year . what percentage has the value of your holdings changed by over the past year . 
Options: a ) 45 % , b ) 46 % , c ) 50 % , d ) 55 % , e ) 44 %
e

Problem: a milk man has 15 liters of milk . if he mixes 5 liters of water , which is freely available , in 20 liters of pure milk . if the cost of pure milk is rs . 18 per liter , then the profit of the milkman , when he sells all the mixture at cost price is : 
Options: a ) 20 % , b ) 25 % , c ) 33.33 % , d ) 18 % , e ) none of these

a