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: if each year the population of the country grows by 40 % , how many years will elapse before the population of the country doubles ? 
Options: a ) 3 , b ) 4 , c ) 5 , d ) 6 , e ) 7

Answer: a


Question: Problem: a number increased by 20 % gives 480 . the number is ? 
Options: a ) 200 , b ) 300 , c ) 400 , d ) 500 , e ) 600

Answer: c


Question: Problem: peter invests a sum of money and gets back an amount of $ 815 in 3 years . david invests an equal amount of money and gets an amount of $ 870 in 4 years . if both amounts were invested at the same rate ( simple interest ) what was the sum of money invested ? 
Options: a ) 670 , b ) 650 , c ) 698 , d ) 744 , e ) 700

Answer:
b