Bunuel wrote:
An airplane was due north of a tropical island when hurricane warning arrived at noon. In what direction was the tropical island from the position of the airplane at 3 pm?
(1) To circumvent the path of the hurricane, the airplane flew due west at 200 miles per hour from noon till 2 pm, and from 2 pm until 3 pm, it flew due south at 300 miles per hour.
(2) At 3 pm, the airplane was exactly 450 miles from the tropical island.
I used coordinate geometry to solve this question.
Since I cannot draw here, please bear with me. I will try and explain my process.
At 12 pm - Plane is due north of the island, so if the island is at coordinate (0,0), then the plane is at (0,y).
Storm warning. Where is the plane relative to the island at 3pm? Or what are the coordinates?
1) Plane flew west from (0,y) at 200 miles per hour till 2 pm
Plane's new position is (-400,y)
Plane flew south from (-400,y) at 300 miles per hour for 1 hour.
Plane's new position is (-400,y-300)
y=?
Insufficient.
2) At 3 pm the plane is 450 miles from the island
It should be in any direction. Insufficient.
(1+2)
Plane's last known position is (-400, y-300)
The distance is 450 miles from the island.
If y > 300 then it's above the x-axis and if y < 300 then it's below the x-axis.
Insufficient.
Answer is E.
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