The task is to generate the correct answer for a given math problem.

Example Input: Problem: two trains travel in opposite directions at 36 kmph and 45 kmph and a man sitting in slower train passes the faster train in 12 seconds . the length of the faster train is
Example Output: 270 m

Example Input: Problem: a train running at the speed of 72 km / hr crosses a pole in 9 seconds . find the length of the train .
Example Output: 180 meter

Example Input: Problem: a man sells a car to his friend at 10 % loss . if the friend sells it for rs . 54000 and gains 20 % , the original c . p . of the car was :
Example Output:
rs . 50000