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