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: at the end of the month , a certain ocean desalination plant ’ s reservoir contained 26 million gallons of water . this amount is eighth the normal level . if this amount represents 65 % of the reservoir ’ s total capacity , how many million gallons short of total capacity is the normal level ? 
Options: a ) 15 , b ) 25 , c ) 35 , d ) 45 , e ) 55
c

Problem: the price of a book is increased from $ 300 to $ 480 . what is the % of increase in its price ? 
Options: a ) 10 % , b ) 20 % , c ) 40 % , d ) 50 % , e ) 60 %
e

Problem: in an election , candidate a got 75 % of the total valid votes . if 15 % of the total votes were declared invalid and the total numbers of votes is 560000 , find the number of valid vote polled in favour of candidate 
Options: a ) 356000 , b ) 356500 , c ) 357000 , d ) 400000 , e ) none of these

c