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'.
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Question: Problem: 40 is subtracted from 70 % of a number , the result is 30 . find the number ? 
Options: a ) 150 , b ) 997 , c ) 266 , d ) 288 , e ) 100

Answer: e


Question: 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

Answer: c


Question: Problem: two pipes a and b can separately fill a cistern in 60 min and 75 min respectively . there is a third pipe in the bottom of the cistern to empty it . if all the 3 pipes are simultaneously opened , then the cistern is full in 50 min . in how much time , the third pipe alone can empty the cistern ? 
Options: a ) 197 min , b ) 100 min , c ) 177 min , d ) 176 min , e ) 186 min

Answer:
b