Task: Question Answering
Input (English): Problem: the ratio of the arithmetic mean of two numbers to one of the numbers is 3 : 5 . what is the ratio of the smaller number to the larger ? 
Options: a ) 1 : 5 , b ) 1 : 4 , c ) 1 : 3 , d ) 1 : 2 , e ) 2 : 3
Output (English): a