Task: Question Answering
Input (English): Problem: the cross - section of a cannel is a trapezium in shape. if the cannel is 12 m wide at the top and 2 m wide at the bottom and the area of cross - section is 4200 sq m, the depth of cannel is ?
Options: a. 500, b. 600, c. 700, d. 800, e. 900
Output (English): b