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'.

[EX Q]: 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
[EX A]: c

[EX Q]: Problem: rs . 200 amounts to rs . 800 in 8 years at simple interest . if the interest is increased by 5 % , it would amount to how much ? 
Options: a ) 520 , b ) 440 , c ) 260 , d ) 280 , e ) 120
[EX A]: d

[EX Q]: Problem: a trader mixes 80 kg of tea at 15 per kg with 20 kg of tea at cost price of 20 per kg . in order to earn a profit of 25 % , what should be the sale price of the mixed tea ? 
Options: a ) 23.75 , b ) 22 , c ) 20 , d ) 19.20 , e ) none of these
[EX A]:
c