Task: Question Answering
Input (English): Problem: the cross - section of a cannel is a trapezium in shape . if the cannel is 15 m wide at the top and 9 m wide at the bottom and the area of cross - section is 636 sq m , the depth of cannel is ? 
Options: a ) 53 , b ) 28 , c ) 27 , d ) 80 , e ) 25
Output (English): a