Two trains travel toward each other on the same track, beginning 100 miles apart. One train travels at 40 miles per hour; the other travels at 60 miles an hour. A bird starts flight at the same location as the faster train, flying at a speed of 90 miles per hour. When it reaches the slower train, it turns around, flying the other direction at the same speed. When it reaches the faster train again, it turns around -- and so on. When the trains collide?

• Ignore the bird bcoz bird is not affecting train's speed or direction. So, in 1 hr,both trains will collide as slower train will travel 40 miles and another train 60 miles in one hr. so, they ll collide after 1 hr.
• 9 years agoHelpfull: Yes(4) No(0)
• x: Time at which the two trains collide
  100-40x=60x ====> x=1hr
  
  x: Time at which the bird and train B collide
  
  100-40x = 90x ====> x= 10/13 hr
  
  90(10/13) - 90 ( 3/13) = 48 miles
  
• 9 years agoHelpfull: Yes(3) No(1)
• bird travel 90 miles
  bcoz time to collide train=100/40+60=1hour
  so bird trave in 1 hour =90 miles
• 10 years agoHelpfull: Yes(2) No(7)