Task: Question Answering
Input (English): Problem: a , b and c enter into partnership . a invests some money at the beginning , b invests double the amount after 6 months , and c invests thrice the amount after 8 months . if the annual gain be rs . 15000 . a ' s share is ? 
Options: a ) 2999 , b ) 2778 , c ) 6000 , d ) 5000 , e ) 6612
Output (English): d