Task: Question Answering
Input (English): Problem: the ratio of the present ages of ramesh and mahesh is 2 : 5 . 10 years hence , the ratio of their ages will be 10 : 15 . find the difference in their present ages ? 
Options: a ) 7.5 , b ) 6 , c ) 5.5 , d ) 6.5 , e ) 5
Output (English): a