ratios

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ratios

by vaibhav101 » Thu May 31, 2018 7:55 am

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Each member a pack of 55 wolves has either brown or blue eyes and either a white or a grey coat. If there are more than 3 blue-eyed wolves with white coats , are there more blue-eyed wolves then brown-eyed wolves ?

1) among the blue-eyed wolves, the ratio of grey coats to white coats is 4 to 3
2) among the brown-eyed wolves, the ratio of white coats to grey coats is 2 to 1

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by GMATGuruNY » Thu May 31, 2018 8:32 am

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vaibhav101 wrote:Each member a pack of 55 wolves has either brown or blue eyes and either a white or a grey coat. If there are more than 3 blue-eyed wolves with white coats , are there more blue-eyed wolves then brown-eyed wolves ?

1) among the blue-eyed wolves, the ratio of grey coats to white coats is 4 to 3
2) among the brown-eyed wolves, the ratio of white coats to grey coats is 2 to 1
Statement 1: Among the blue-eyed wolves, the ratio of grey coats to white coats is 4:3.
Since (blue-eyed grey):(blue-eyed white) = 4:3 -- and 4+3 = 7 -- the total number of blue-eyed wolves must be a MULTIPLE OF 7.
Since there are MORE THAN 3 blue-eyed white wolves, the least possible case is as follows:
blue-eyed grey = 8 and blue-eyed white = 6, for a total of 14 blue-eyed wolves.
No information about the number of brown-eyed wolves.
INSUFFICIENT.

Statement 2: Among the brown-eyed wolves, the ratio of white coats to grey coats is 2:1.
Since (brown-eyed white):(brown-eyed grey) = 2:1 -- and 2+1 = 3 -- the total number of brown-eyed wolves must be a MULTIPLE OF 3.
No information about the number of blue-eyed wolves.

Statements combined:
Since the number of blue-eyed wolves must be a multiple of 7 greater than or equal to 14, and the total number of wolves = 55, we get the following options:
total blue-eyed = 14, total brown-eyed = 55-14 = 41.
total blue-eyed = 21, total brown-eyed = 55-21 = 34.
total blue-eyed = 28, total brown-eyed = 55-28 = 27.

The option in red represents the least total number of blue-eyed wolves that yields a multiple of 3 for the total number of brown-eyed wolves.
Since the least total number of blue-eyed wolves (28) is more than half the total number of wolves (55), there must be MORE BLUE-EYED WOLVES THAN BROWN-EYED WOLVES.
SUFFICIENT.

The correct answer is C.
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