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

[EX Q]: Problem: a and b are 90 km apart they start to move each other simultaneously a at speed 10 and b at 5 km / hr if every hour they double their speed what is distance that a pass until he meet b ?
[EX A]: 60 km

[EX Q]: Problem: a person was asked to subtract 25 % of a number from the original but he subtracted 25 from the number . his answer was 25 more than correct one . what was the original number ?
[EX A]: 200

[EX Q]: Problem: a train of 30 carriages , each of 60 meters length , when an engine also of 60 meters length is running at a speed of 60 kmph . in what time will the train cross a bridge 1.5 km long ?
[EX A]:
3.3