Data Sufficiency

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

BTGmoderatorDC wrote: ↑

Mon Aug 17, 2020 6:22 pm

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.

Statement 1;
Between 9am and 4pm -- a total of 7 hours -- the total distance traveled by the train = (200 north of the bridge) + (10-mile bridge) + (140 miles south of the bridge) = 200+10+140 = 350 miles.
Since 350 miles are traveled in 7 hours, the train's rate = d/t = 350/7 = 50 mph.
Distance traveled in the 5 hours between 9am and 2pm = rt = 50*5 = 250 miles.
Since the 250 miles traveled by 2pm is 40 miles greater than the 210-mile blue distance above, the train at 2pm must be 40 miles south of the bridge.
Thus, the answer to the question stem is NO.
SUFFICIENT.

Statement 2:
No information about the distance between the 6am starting point and the location of the bridge.
INSUFFICIENT.

The correct answer is A.