Task: Question Answering
Input (English): Problem: if 4 men working 10 hours a day earn rs . 1600 per week , then 9 men working 6 hours a day will earn how much per week ? 
Options: a ) rs 840 , b ) rs 1320 , c ) rs 1620 , d ) rs 2160 , e ) none of these
Output (English): d