Stations X and Y are connected by two separate, straight, parallel rail lines that are 250 miles long. Train P and train Q simultaneously left Station X and Y, respectively, and each train traveled to the other's point of departure. The two trains passed each other after traveling for 2 hours. When the two trains passed, which train was nearer to its destination?
1. At the time when the two trains passed, train P had averaged a speed of 70MPH.
2. Train Q averaged a speed of 55 miles per hour for the entire trip.
The OA is A, but I get E. [spoiler]In 1, we don't know how fast train Q was going. In 2, we don't know how fast train P was going. And combined we don't know if train Q continued it's rate or not.[/spoiler] What is wrong with my reasoning?
Thanks
Two trains
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A useful website I found that has every quant OG video explanation:
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- Birottam Dutta
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In the question it is written that they passed each other after 2 hours.
1) P averaged 70 MPH when they passed, so P must have covered 70*2 = 140 Miles in that time.
Hence, P was nearer to the destination.
1 is sufficient.
2 is not sufficient for the exact reason stated by you.
Hence, A!
1) P averaged 70 MPH when they passed, so P must have covered 70*2 = 140 Miles in that time.
Hence, P was nearer to the destination.
1 is sufficient.
2 is not sufficient for the exact reason stated by you.
Hence, A!
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