An air traveler in Beijing cannot fly to Lhasa without first flying to Chengdu. Unfortunately, an air traveler in Be...

Mehran September 4, 2018

Hi @ Kyra, thanks for your post. The correct answer here is (B).

Let's analyze the stimulus. This one presents an argument, as follows:
P: An air traveler in Beijing cannot fly to Lhasa without first flying to Chengdu.
(If Beijing to Lhasa, then fly through Chengdu)
B to L ==> Ch

P: An air traveling in Beijing must fly to Xian before flying to Chengdu.
(If Chengdu, then Xian)
Ch ==> X

C: Any air traveler who flies from Beijing to Lhasa cannot avoid flying to Xian.
B to L ==> X
(via transitive property combining premises 1 & 2)

Answer choice (B) parallels this reasoning.
P: An ice-sculpture artist cannot reach the yellow level of achievement without first achieving the green level.
(If yellow level, then green level first)
Y ==> G

P: The green level is impossible to achieve unless the white level has already been achieved.
(If green, then white level first)
G ==> W

C: Therefore, an ice-sculpture artist who has reached the yellow level must have previously achieved the white level.
Y ==> W
(yes, via transitive property combining premises 1 & 2)

Kyra September 17, 2018

Thanks Mehran!

niki-dowlatshahi September 29, 2018

can't you also do a transitive chain with this question?
Beijing -> Xian -> Chengdu -> Lhasa
then answer B does the same link chain which is the answer?
I just think its simpler to think of it as a linear statement without making it an argument, even though it may be one