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vivek.kapoor83
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imo 7/12
whats OA?
you posted ques in both forums?
tuf ques
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Source: Beat The GMAT — Problem Solving |
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vivek.kapoor83
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i wrongly posted there. Sorry
But. i am very confused with the statement ans ratio def given at last. why need that
OA is 7/12
you pls explain ur ans
But. i am very confused with the statement ans ratio def given at last. why need that
OA is 7/12
you pls explain ur ans
let the total numnber of geese be x
total male = 0.3x, total female = 0.7x
let those migrated be y
num of male migrated = 0.2y
number of female migrated = 0.8y
male migration ratio = 0.2y/0.3x = 2y/3x
female migration ratio = 0.8y/0.7x = 8y/7x
male ratio/female ratio = [2y/3x]/[8y/7x] = 2y*7x/8y*3x = 7/12
total male = 0.3x, total female = 0.7x
let those migrated be y
num of male migrated = 0.2y
number of female migrated = 0.8y
male migration ratio = 0.2y/0.3x = 2y/3x
female migration ratio = 0.8y/0.7x = 8y/7x
male ratio/female ratio = [2y/3x]/[8y/7x] = 2y*7x/8y*3x = 7/12
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cramya
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Try picking numbers.
Lets say ther eare 100 geese in total
30 are male
70 are female.
Pick a number (easy to work with with division/multiplication etc..) lets say 80 geese migrated
20% of 80 were male i.e 20/100*80 = 16
64 were female(remaining 80%)
So No of males migrated to No of female migrated
= (Migrated male geese / Total male geese) / (Migrated Female geese / Total Female geese)
= 16/30 / 64/80
= 16/30 * 80/64
= 7/12
Lets say ther eare 100 geese in total
30 are male
70 are female.
Pick a number (easy to work with with division/multiplication etc..) lets say 80 geese migrated
20% of 80 were male i.e 20/100*80 = 16
64 were female(remaining 80%)
So No of males migrated to No of female migrated
= (Migrated male geese / Total male geese) / (Migrated Female geese / Total Female geese)
= 16/30 / 64/80
= 16/30 * 80/64
= 7/12
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cramya
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- Posts: 2467
- Joined: Thu Aug 28, 2008 6:14 pm
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Corrected typo in previous post (in bold)
Try picking numbers.
Lets say ther eare 100 geese in total
30 are male
70 are female.
Pick a number (easy to work with with division/multiplication etc..) lets say 80 geese migrated
20% of 80 were male i.e 20/100*80 = 16
64 were female(remaining 80%)
So No of males migrated to No of female migrated
= (Migrated male geese / Total male geese) / (Migrated Female geese / Total Female geese)
= 16/30 / 64/70
= 16/30 * 70/64
= 7/12
Try picking numbers.
Lets say ther eare 100 geese in total
30 are male
70 are female.
Pick a number (easy to work with with division/multiplication etc..) lets say 80 geese migrated
20% of 80 were male i.e 20/100*80 = 16
64 were female(remaining 80%)
So No of males migrated to No of female migrated
= (Migrated male geese / Total male geese) / (Migrated Female geese / Total Female geese)
= 16/30 / 64/70
= 16/30 * 70/64
= 7/12
