The task is to generate the correct answer for a given math problem.
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Question: Problem: ? x 12 = 173 x 240

Answer: 3460


Question: Problem: if each participant of a chess tournament plays exactly one game with each of the remaining participants , then 153 games will be played during the tournament . find the number of participants .

Answer: 18


Question: Problem: two bullet train s 140 m and 200 m long run at the speed of 60 km / hr and 40 km / hr respectively in opposite directions on parallel tracks . the time ( in seconds ) which they take to cross each other , is :

Answer:
12.24 sec .