Two trains starting at the same time from 2 stations 200 km apart and going in opposite direction cross each other at a distance of 110 km from one of the stations. What is the ratio of their speeds?

In the same time, they cover 110 km and 90 km respectively.

For the same time, speed and distance is inversely proportional.

So ratio of their speed = 110:90 = 11: 9