From two cities two trains Some each other meet halfway passed 80 km that makes 2/5 distance between the cities, and another a half of distance between the cities How many kilometers needed to be passed to trains prior to a meeting

2/5=80 km 1/5=40 km 5/5 = 200 km are a distance between the cities the first passed 80 km, and the second a half of the general distance, i.e. 200/2=100 km together they passed 100+80=180 km Therefore prior to a meeting to them it was necessary to pass 200-180= of 20 km
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