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

Example Input: Problem: if 2 men or 3 women can reap a field in 10 days how long will 4 men and 5 women take to reap it ?
Example Output: 11 / 30

Example Input: Problem: a man whose speed is 4.5 kmph in still water rows to a certain upstream point and back to the starting point in a river which flows at 1.5 kmph , find his average speed for the total journey ?
Example Output: 4

Example Input: Problem: a man can row a distance of 6 km in 60 min with the help of the tide . the direction of the tide reverses with the same speed . now he travels a further 20 km in 10 hours . how much time he would have saved if the direction of tide has not changed ?
Example Output:
6 : 41