Task: Question Answering
Input (English): Problem: two trains are moving in opposite directions at 60 km / hr and 90 km / hr. their lengths are 1.15 km and 0.6 km respectively. the time taken by the slower train to cross the faster train in seconds is ?
Options: a. 42, b. 9, c. 7, d. 67, e. 15
Output (English): a