Task: Question Answering
Input (English): Problem: a hall is 15 meters long and 10 meters wide. if the sum of the areas of the floor and the ceiling is equal to the sum of the areas of four walls, what is the volume of the hall ( in cubic meters ) ?
Options: a. 600, b. 700, c. 800, d. 900, e. 1000
Output (English): d