Task: Question Answering
Input (English): Problem: a certain elevator has a safe weight limit of 2,000 pounds. what is the greatest possible number of people who can safely ride on the elevator at one time with the average ( arithmetic mean ) weight of half the riders being 200 pounds and the average weight of the others being 230 pounds ?
Options: a. 7, b. 8, c. 9, d. 10, e. 11
Output (English): c