Task: Question Answering
Input (English): Problem: a rower can row 7 km / h in still water. when the river is running at 2 km / h, it takes the rower 1 hour to row to big rock and back. how many kilometers is it to big rock ?
Options: a. 2.92, b. 3.04, c. 3.12, d. 3.21, e. 3.35
Output (English): d