In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

[Q]: Problem: if 15 ! / 3 ^ x is an integer , what is the greatest possible value of x ? 
Options: a ) 3 , b ) 4 , c ) 5 , d ) 6 , e ) 7
[A]: d


[Q]: Problem: a customer bought a product at the shop . however , the shopkeeper increased the price of the product by 10 % so that the customer could not buy the required amount of the product . the customer managed to buy only 80 % of the required amount . what is the difference in the amount of money that the customer paid for the second purchase compared to the first purchase ? 
Options: a ) 10 % , b ) 12 % , c ) 14 % , d ) 16 % , e ) 18 %
[A]: b


[Q]: Problem: a dishonest dealer claims to sell a product at its cost price . he uses a counterfeit weight which is 20 % less than the real weight . further greed overtook him and he added 35 % impurities to the product . find the net profit percentage of the dealer ? 
Options: a ) 44 % , b ) 40 % , c ) 68.75 % , d ) 56.25 % , e ) 36 %
[A]:
c