Zoo animal ratios

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Zoo animal ratios

by Brent@GMATPrepNow » Sun Dec 21, 2008 9:29 am
At a certain zoo, the ratio of elephants to deer is 2 to 3, and the ratio of bison to moose is 4 to 5. If the ratio of bison to deer is 1:2, what is the ratio of moose to elephants?
A) 3:5
B) 8:9
C) 15:16
D) 16:15
E) 5:3

Answer: C
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Re: Zoo animal ratios

by logitech » Sun Dec 21, 2008 9:39 am
E/D = 2/3
B/M = 4/5
B/D = 1/2

M/E = ?

M/E = (D/E)(B/D)(M/B) = 3/2 x 1/2 x 5/4 = 15/16
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by mals24 » Sun Dec 21, 2008 9:40 am
E: D = 2:3
B:M = 4:5
B: D = 1:2
M:E = ?

E: D = 2:3 (multiply by 2)
B: D = 1:2 (multiply by 3)

E: D = 4:6
B: D = 3:6

E: D:B = 4:6:3
E:B = 4:3 (multiply by 4)
B:M = 4:5 (multiply by 3)

E:B = 16:12
B:M = 12:15
E:B:M = 16:12:15
E:M = 16:15
M:E = 15:16.

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by ronniecoleman » Sun Dec 21, 2008 10:09 am
At a certain zoo, the ratio of elephants to deer is 2 to 3, and the ratio of bison to moose is 4 to 5. If the ratio of bison to deer is 1:2, what is the ratio of moose to elephants?
A) 3:5
B) 8:9
C) 15:16
D) 16:15
E) 5:3

Ele / deer = 2/3

bison/ moose = 4/5

bison/ deer = 1:2

deer/moose = 8/5

C
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by cramya » Sun Dec 21, 2008 11:38 am
I will also take the pleasure of sovingthis with descriptive names. :-) (for extra credit)

elephant/deer = 2/3

elephant = 2 deer/3

bison/moose = 4/5

moose = 5 bison /4

bison /deer = 1/2 -> deer = 2 bison


Moose / elephant = 5 bison /4 / 2 deer/3
= 5 bison / 4 / 2 (2*bison) /3
= 15/16