Task: Question Answering
Input (English): Problem: in what ratio must rice of rs . 30 per kg be mixed with rice of rs . 56 per kg so that cost of mixture is rs . 35 per kg ? 
Options: a ) 28 : 15 , b ) 6 : 7 , c ) 7 : 6 , d ) 5 : 21 , e ) 21 : 5
Output (English): e