BTGmoderatorDC wrote:Today, Samson's Train traveled at a constant rate along a straight North-South route that included the famous 10-mile long Chasm Bridge. Was Samson's Train on the Chasm Bridge at 2:00 p.m.?

(1) At 9:00 a.m., Samson's Train was 200 miles north of the Chasm Bridge, and at 4:00 p.m, the train was 140 miles south of Chasm Bridge.

(2) Samson's Train started its trip at 6:00 a.m., and traveled at a rate of less than 70 miles per hour.

OA A

Source: Manhattan Prep

Let's take each statement one by one.

(1) At 9:00 a.m., Samson's Train was 200 miles north of the Chasm Bridge, and at 4:00 p.m, the train was 140 miles south of Chasm Bridge.

=> In 9 - 4 = 5 hours, Samson travelled 200 + 140 = 340 miles. Since his speed is constant, his average speed throughout the journey = 340/5 = 68 mph. Sufficient.

(2) Samson's Train started its trip at 6:00 a.m., and traveled at a rate of less than 70 miles per hour.

Certainly insufficient.

The correct answer: A

Hope this helps!

-Jay
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