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: a cyclist rides a bicycle 7 km at an average speed of 10 km / hr and again travels 10 km at an average speed of 7 km / hr . what is the average speed for the entire trip ? 
Options: a ) 7.59 , b ) 7.79 , c ) 7.99 , d ) 8.19 , e ) 8.39

Output: c


Input: Consider Input: Problem: the product of two numbers is 2028 and their h . c . f is 13 . the number of such pairs is : 
Options: a ) 1 , b ) 2 , c ) 3 , d ) 4 , e ) 5

Output: b


Input: Consider Input: Problem: 20 ^ 10 / 120 ^ 5 = ? 
Options: a ) 6 ^ 5 , b ) 5 ^ 6 , c ) ( 10 / 3 ) ^ 5 , d ) 6 ^ 3 , e ) 15 ^ 3


Output: c