SOLUTION: A jogger has attempted to run across a railroad bridge, but sees a train coming after completing 3/4 of the trip. If the train is traveling at 30km/h, and if it is possible for the

Question 1128955: A jogger has attempted to run across a railroad bridge, but sees a train coming after completing 3/4 of the trip. If the train is traveling at 30km/h, and if it is possible for the jogger to just escape being hit by the train by running at full speed to either end of the bridge, what is the minimum speed in km/h that this jogger must be able to run?
A)15 B)20 C)12 D)18 E)25
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
A jogger has attempted to run across a railroad bridge, but sees a train coming after completing 3/4 of the trip.
If the train is traveling at 30km/h, and if it is possible for the jogger to just escape being hit by the train by running at full speed to either end of the bridge, what is the minimum speed in km/h that this jogger must be able to run?
:
We know the jogger will run 1/4 of the bridge just as the train enters the entrance to the bridge.
Going the other way he would also travel 1/4 of the way when the train enters the bridge.
That means he has 2/4 or 1/2 of the bridge to go just as the train enters the bridge.
He has to travel 1/2 of the bridge while the train travels the whole length.
therefore
His speed has to be: *30 = 15 km/hr
:
Did this make sense to you?
RELATED QUESTIONS
A jogger has attempted to run across a railroad bridge, but sees a train coming after... (answered by ikleyn)

Ian is standing 1.4 miles across a 2 mile railroad bridge when he sees a train... (answered by ankor@dixie-net.com)

A man came upon a bridge, he knew a train was coming soon, but he thought he could make... (answered by ankor@dixie-net.com)

2nd question (and last) that I am helping my daughter with...I can not seem to place... (answered by PBMathandscience)

A man is walking on a railroad bridge that goes from A to B. When he is 3/8 the way... (answered by richwmiller)

Sai is on a railroad bridge 3/8 of the way from Helena to Pelham. A train is heading his (answered by ankor@dixie-net.com)

A man walking acros a train bridge is 0.65 of the way across the bridge when he hears a... (answered by ankor@dixie-net.com)

Jon was walking across a bridge one day. He knew that a train was due to come across the... (answered by ankor@dixie-net.com)

A man walking on a railroad bridge is 2/5 of the way along the bridge when he notices a... (answered by ikleyn)