Task: Question Answering
Input (English): Problem: jack and jill are marathon runners. jack can finish a marathon ( 40 km ) in 4.5 hours and jill can run a marathon in 4.0 hours. what is the ratio of their average running speed ? ( jack: jill )
Options: a. 14 / 15, b. 15 / 14, c. 8 / 9, d. 5 / 4, e. can not be determined
Output (English): c