Task: Question Answering
Input (English): Problem: a truck driver starts with the speed of 70 kmph with the truck driver decreasing speed every two hours by 10 kmph . the truck driver ' s speed does not drop below 50 kmph . in how many hours will it take the truck driver to travel 500 kms ? 
Options: a ) 480 minutes , b ) 492 minutes , c ) 504 minutes , d ) 528 minutes , e ) 540 minutes
Output (English): d