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'.

Input: Consider Input: Problem: if 7 a - 3 b = 10 b + 50 = - 12 b - 2 a , what is the value of 9 a + 9 b ? 
Options: a ) - 9 , b ) - 6 , c ) 0 , d ) 6 , e ) 9

Output: c


Input: Consider Input: Problem: a room is 6 meters 24 centimeters in length and 4 meters 32 centimeters in width . find the least number of square tiles of equal size required to cover the entire floor of the room . 
Options: a ) 107 , b ) 117 , c ) 127 , d ) 137 , e ) 147

Output: b


Input: Consider Input: Problem: the average age of a group of 10 persons was decreased by 3 years when one person , whose age was 42 years , was replaced by a new person . find the age of the new person ? 
Options: a ) 22 , b ) 18 , c ) 12 , d ) 88 , e ) 66


Output: c