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'.

Input: Consider Input: Problem: joe invested a certain sum of money in a simple interest bond whose value grew to $ 310 at the end of 3 years and to $ 410 at the end of another 5 years . what was the rate of interest in which he invested his sum ? 
Options: a ) 6 % , b ) 7 % , c ) 8 % , d ) 9 % , e ) 10 %

Output: c


Input: Consider Input: Problem: a ladder 14 feet long is leaning against a wall that is perpendicular to level ground . the bottom of the ladder is 5 feet from the base of the wall . if the top of the ladder slips down 4 feet , how many feet will the bottom of the ladder slip ? 
Options: a ) 4 , b ) 5 , c ) 8 , d ) 10.72 , e ) 15

Output: d


Input: Consider Input: Problem: i sold a book at a profit of 10 % . had i sold it for $ 90 more , 15 % would have been gained . find the cost price ? 
Options: a ) $ 1800 , b ) $ 2500 , c ) $ 3000 , d ) $ 3120 , e ) $ 1540


Output: a