The task is to generate the correct answer for a given math problem.
--------
Question: Problem: a can do a work in 15 days and b in 20 days . if they work on it together for 5 days , then the fraction of the work that is left is

Answer: 5 / 12


Question: Problem: a hiker walking at a constant rate of 4 kilometers per hour is passed by a cyclist travelling in the same direction along the same path at a constant rate of 24 kilometers per hour . the cyclist stops and waits for the hiker 5 minutes after passing her while the hiker continues to walk at her constant rate . how many minutes must the cyclist wait until the hiker catches up ?

Answer: 25


Question: Problem: a train which has 500 m long , is running 100 kmph . in what time will it cross a person moving at 10 kmph in same direction ?

Answer:
20 sec