SOLUTION: 2 trains starts at the same times but in opposite directions. their speed are 80 km/hr and 90 km/hr. after how long will they be 850 km apart?

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Question 881836: 2 trains starts at the same times but in opposite directions. their speed are 80 km/hr and 90 km/hr. after how long will they be 850 km apart?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
D = rt
80t + 90t = 850km
170t = 850km
t = 850km/(170kmph) = 5 hr