Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized for You
we will pick new questions that match your level based on your Timer History
Track Your Progress
every week, we’ll send you an estimated GMAT score based on your performance
Practice Pays
we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:
A certain zoo has exactly five types of animals: alligators, buffalo,
[#permalink]
Show Tags
05 Aug 2018, 08:04
Top Contributor
00:00
A
B
C
D
E
Difficulty:
35% (medium)
Question Stats:
70% (02:15) correct 30% (01:56) wrong based on 46 sessions
HideShow timer Statistics
A certain zoo has exactly five types of animals: alligators, buffalo, camels, deer and elephants. The ratio of the number of alligators to buffalo to camels is 4 : 3 : 1. The ratio of the number deer to elephants to buffalo is 6 : 1 : 4. Which of the following could represent the total animal population at the zoo?
Re: A certain zoo has exactly five types of animals: alligators, buffalo,
[#permalink]
Show Tags
05 Aug 2018, 08:32
GMATPrepNow wrote:
A certain zoo has exactly five types of animals: alligators, buffalo, camels, deer and elephants. The ratio of the number of alligators to buffalo to camels is 4 : 3 : 1. The ratio of the number deer to elephants to buffalo is 6 : 1 : 4. Which of the following could represent the total animal population at the zoo?
Re: A certain zoo has exactly five types of animals: alligators, buffalo,
[#permalink]
Show Tags
05 Aug 2018, 09:00
GMATPrepNow wrote:
A certain zoo has exactly five types of animals: alligators, buffalo, camels, deer and elephants. The ratio of the number of alligators to buffalo to camels is 4 : 3 : 1. The ratio of the number deer to elephants to buffalo is 6 : 1 : 4. Which of the following could represent the total animal population at the zoo?
A) 88 B) 90 C) 121 D) 159 E) 168
Attachment:
Capture.PNG [ 3.16 KiB | Viewed 313 times ]
Thus the number of animals in the zoo must be multiple of 53 ( ie , 16+12+4+18+3), Answer must be (D) _________________
Thanks and Regards
Abhishek....
PLEASE FOLLOW THE RULES FOR POSTING IN QA AND VA FORUM AND USE SEARCH FUNCTION BEFORE POSTING NEW QUESTIONS
WE: Supply Chain Management (Energy and Utilities)
Re: A certain zoo has exactly five types of animals: alligators, buffalo,
[#permalink]
Show Tags
05 Aug 2018, 09:27
GMATPrepNow wrote:
A certain zoo has exactly five types of animals: alligators, buffalo, camels, deer and elephants. The ratio of the number of alligators to buffalo to camels is 4 : 3 : 1. The ratio of the number deer to elephants to buffalo is 6 : 1 : 4. Which of the following could represent the total animal population at the zoo?
A certain zoo has exactly five types of animals: alligators, buffalo,
[#permalink]
Show Tags
05 Aug 2018, 15:08
1
GMATPrepNow wrote:
A certain zoo has exactly five types of animals: alligators, buffalo, camels, deer and elephants. The ratio of the number of alligators to buffalo to camels is 4 : 3 : 1. The ratio of the number deer to elephants to buffalo is 6 : 1 : 4. Which of the following could represent the total animal population at the zoo?
A) 88 B) 90 C) 121 D) 159 E) 168
We have two ratios. A : B : C 4 : 3 : 1
D :E : B 6 : 1 : 4
B is the term common to both ratios. B's value in both ratios must be equal. Right now the values for B are not equal. Take the LCM of 3 and 4 = 12.
In order to get B to = 12 in both ratios, multiply all numbers in the first ratio by 4 and all numbers in the second ratio by 3. (What we do to one part of a ratio we must do to all parts.)
First ratio: every number * 4 A : B : C (4 : 3 : 1) ==> \(* 4\) 16 : 12 : 4
Second ratio: every number * 3 D : E : B (6 : 1 : 4) ==> \(* 3\) 18 : 3 : 12
Combine the results A : B : C : D : E 16:12 : 4 : 18 : 3
Sum the parts of the new ratio (With \(x\) I am just making the multiplier explicit) \((16x+12x+4x+18x+3x) = 53x\)
These animals must be in groups of (multiples of) 53.
Only one answer is a multiple of 53 (53 + 3) = 159
Answer D
_________________
In the depths of winter, I finally learned that within me there lay an invincible summer. -- Albert Camus, "Return to Tipasa"
Re: A certain zoo has exactly five types of animals: alligators, buffalo,
[#permalink]
Show Tags
08 Aug 2018, 10:33
Top Contributor
GMATPrepNow wrote:
A certain zoo has exactly five types of animals: alligators, buffalo, camels, deer and elephants. The ratio of the number of alligators to buffalo to camels is 4 : 3 : 1. The ratio of the number deer to elephants to buffalo is 6 : 1 : 4. Which of the following could represent the total animal population at the zoo?
A) 88 B) 90 C) 121 D) 159 E) 168
The ratio of the number of alligators to buffalo to camels is 4 : 3 : 1 So we can write: , A : B : C = 4 : 3 : 1
The ratio of the number deer to elephants to buffalo is 6 : 1 : 4 So we can write: D : E : B = 6 : 1 : 4
Notice that both ratios have a B in common. In order to COMBINE the two ratios, we need to have the same -B-value So, let's write some EQUIVALENT ratios that share the same B-value.
Take the first ratio, 4 : 3 : 1, and multiply all values by 4 to get the equivalent ratio 16 : 12 : 4 In other words, A : B : C = 16 : 12 : 4
Now take the second ratio, 6 : 1 : 4 , and multiply all values by 3 to get the equivalent ratio 18 : 3 : 12 In other words, D : E : B = 18 : 3 : 12
Now that our two ratios have the same B-value (12 ), we can combine the ratios to get... A : B : C : D : E = 16 : 12 : 4 : 18 : 3 So, it's possible that there are 16 alligators, 12 buffalo, 4 camels, 18 deer and 3 elephants for a TOTAL of 53 animals (NOT among the answer choices)
Take our ratio, 16 : 12 : 4 : 18 : 3, and multiply by 2 to get the EQUIVALENT ratio: A : B : C : D : E = 32: 24 : 8 : 36 : 6 So, it's also possible that there are 32 alligators, 24 buffalo, 8 camels, 36 deer and 6 elephants for a TOTAL of 106 animals (NOT among the answer choices)
At this point, we might recognize that the TOTAL number of animals must be a MULTIPLE of 53 Check the answer choices.... Only answer choice D is a MULTIPLE of 53
Answer: D
RELATED VIDEO FROM OUR COURSE
_________________
Brent Hanneson – Founder of gmatprepnow.com
gmatclubot
Re: A certain zoo has exactly five types of animals: alligators, buffalo, &nbs
[#permalink]
08 Aug 2018, 10:33
close
70% (02:15) correct 
