Task: Question Answering
Input (English): Problem: a , b and c enter into a partnership by investing $ 7000 , $ 11000 and $ 18000 respectively . at the end of 8 months , b receives $ 880 as his share . find the share of a . 
Options: a ) $ 320 , b ) $ 440 , c ) $ 560 , d ) $ 670 , e ) $ 780
Output (English): c