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

Q: 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 .

A: 18
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Q: Problem: a train 150 m long is running at a speed of 68 kmph . how long does it take to pass a man who is running at 8 kmph in the same direction as the train ?

A: 9 sec
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Q: Problem: in the coordinate plane , line a has a slope of - 2 and an x - intercept of 2 . line b has a slope of 5 and a y - intercept of - 10 . if the two lines intersect at the point ( a , b ) , what is the sum a + b ?

A:
2
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