Direction PS question.

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Direction PS question.

by aman88 » Sat Dec 22, 2012 5:49 am
Q. While flying over the Pacific, an airplane makes a 25° turn to the right to avoid a storm. If, as a result, the airplane is traveling in a direction 5° east of north, in what direction was it originally flying?

A. 30° west of north
B. 30° east of north
C. 20° west of north
D. 20° east of north
E. 5° west of north

OA C

How to tackle questions like these?

Thanks.

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by GMATGuruNY » Sat Dec 22, 2012 6:19 am
aman88 wrote:Q. While flying over the Pacific, an airplane makes a 25° turn to the right to avoid a storm. If, as a result, the airplane is traveling in a direction 5° east of north, in what direction was it originally flying?

A. 30° west of north
B. 30° east of north
C. 20° west of north
D. 20° east of north
E. 5° west of north

OA C

How to tackle questions like these?

Thanks.
DRAW:

Image

The plane finishes 5º east of north.
Since the plane turned RIGHT 25º to get to this position, rotate 25º TO THE LEFT to determine where the plane started.
As the figure shows, the plane started 20º west of north.

The correct answer is C.
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by puneetkhurana2000 » Sat Dec 22, 2012 12:53 pm
As all options have north as the keyword, so use North as the dividing line, so if now the airplane is on east of north, then originally it must have been west of north.

Rule out options B and D, now west of north is (25° - 5°) = 20°.

Answer C.

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by vishugogo » Sun Dec 23, 2012 10:02 am
In these questions a diagram helps most.

IMO C