Events & Promotions
|
|
GMAT Club Daily Prep
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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Jun 3008:00 AM PDT
-11:59 PM PDT
Join us June 30th for 2 weeks of GMAT questions (just 8 per day) to help with your prep and to compete with your fellow GMAT Clubbers for a chance to win a prize fund of $30,000 for you and your team-mates!
Jul 0901:00 PM EDT
-02:00 PM EDT
More Target Test Prep students are earning 100th percentile GMAT scores. Don’t settle for less when the Target Test Prep course gives you everything you need to score high on the GMAT. Start your 5-day free trial today.
Jul 1206:30 AM PDT
-08:30 AM PDT
Join our webinar to master GMAT RC Main Point Questions! Learn effective strategies to decipher passage themes and purposes. Senior Verbal Expert- Sunita Singhvi will equip you with tools to navigate complexities and avoid common traps set by the GMAT.
Jul 1211:00 AM IST
-01:00 PM IST
Attend this session to learn how to Deconstruct arguments, Pre-Think Author’s Assumptions, and apply Negation Test.
Jul 1311:00 AM EDT
-12:30 PM EDT
Looking for your GMAT motivation to break through the score plateau? Pragati improved her score by massive 160 points with strategic guidance and hard-work! Find out how personalized mentorship and a strong mindset can turn GMAT struggles into success.
Jul 1508:00 PM PDT
-09:00 PM PDT
Full-length FE mock with insightful analytics, weakness diagnosis, and video explanations!
Jul 1611:00 AM EDT
-12:00 PM EDT
Prefer video-based learning? The Target Test Prep OnDemand course is a one-of-a-kind video masterclass featuring 400 hours of lecture-style teaching by Scott Woodbury-Stewart, founder of Target Test Prep and one of the most accomplished GMAT instructors.
20 Dec 2024, 09:00
Kudos
Bookmarks
A
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
95%
(hard)
Question Stats:
26% (02:11) correct
74%
(02:03)
wrong
based on 282
sessions
History
Date
Time
Result
Not Attempted Yet
12 Days of Christmas 2024 - 2025 Competition with $40,000 of Prizes
On a farm with a total of 72 animals, some are goats, and the rest are cows. If there is at least one goat and at least one cow, what is the positive difference between the number of vaccinated goats and vaccinated cows?
(1) One-fourth of the goats and one-ninth of the cows are vaccinated.
(2) The ratio of vaccinated goats to vaccinated cows is 9 to 4.
On a farm with a total of 72 animals, some are goats, and the rest are cows. If there is at least one goat and at least one cow, what is the positive difference between the number of vaccinated goats and vaccinated cows?
(1) One-fourth of the goats and one-ninth of the cows are vaccinated.
(2) The ratio of vaccinated goats to vaccinated cows is 9 to 4.
|
20 Dec 2024, 10:00
Kudos
Bookmarks
Bunuel
12 Days of Christmas 2024 - 2025 Competition with $40,000 of Prizes
On a farm with a total of 72 animals, some are goats, and the rest are cows. If there is at least one goat and at least one cow, what is the positive difference between the number of vaccinated goats and vaccinated cows?
(1) One-fourth of the goats and one-ninth of the cows are vaccinated.
(2) The ratio of vaccinated goats to vaccinated cows is 9 to 4.
On a farm with a total of 72 animals, some are goats, and the rest are cows. If there is at least one goat and at least one cow, what is the positive difference between the number of vaccinated goats and vaccinated cows?
(1) One-fourth of the goats and one-ninth of the cows are vaccinated.
(2) The ratio of vaccinated goats to vaccinated cows is 9 to 4.
GMAT Club's Official Explanation:
On a farm with a total of 72 animals, some are goats, and the rest are cows. If there is at least one goat and at least one cow, what is the positive difference between the number of vaccinated goats and vaccinated cows?
(1) One-fourth of the goats and one-ninth of the cows are vaccinated.
Assuming there are g goats and 72 - g cows, the positive difference between the number of vaccinated goats and vaccinated cows would be |g/4 - (72 - g)/9| = |13g/36 - 8|. Since the difference must be an integer, 13g/36 must be an integer, meaning that g, the number of goats, must be a multiple of 36. Given that 0 < g < 72, the only possible value of g is 36, making the difference equal to |13g/36 - 8| = 5. Sufficient.
Alternatively, assuming the number of vaccinated goats is m and the number of vaccinated cows is n, we’d get 4m + 9n = 72. From this, we can deduce that m must be a multiple of 9 (for 4m + (a multiple of 9) to equal a multiple of 9). The only non-negative value of m that works is m = 9, giving n = 4, and the difference of m - n = 9 - 4 = 5. Sufficient.
(2) The ratio of vaccinated goats to vaccinated cows is 9 to 4.
If the number of vaccinated goats and cows are 9 and 4, respectively, the difference would be 5. However, if those numbers are 18 and 8, the difference would be 10. We already have two different answers; hence, this statement is not sufficient.
Answer: A
General Discussion
20 Dec 2024, 09:43
Kudos
Bookmarks
On a farm with a total of 72 animals, some are goats, and the rest are cows.
If there is at least one goat and at least one cow, what is the positive difference between the number of vaccinated goats and vaccinated cows?
(1) One-fourth of the goats and one-ninth of the cows are vaccinated.
Since all numbers in the table are integers, x/4 is an integer (72-x)/9 is also an integer
x=72-y is a multiple of 4, 72-x=y is a multiple of 9
x = 36
The difference between the number of vaccinated goats and vaccinated cows = 9 - 4 = 5
SUFFICIENT
(2) The ratio of vaccinated goats to vaccinated cows is 9 to 4.
Case 1: k = 1
The difference between the number of vaccinated goats and vaccinated cows = 9 - 4 = 5
Case 2: k = 2
The difference between the number of vaccinated goats and vaccinated cows = 18 - 8 = 10
NOT SUFFICIENT
IMO A
If there is at least one goat and at least one cow, what is the positive difference between the number of vaccinated goats and vaccinated cows?
| Goats | Cows | Total | |
| Vaccinated | |||
| Not vaccinated | |||
| Total | 72 |
(1) One-fourth of the goats and one-ninth of the cows are vaccinated.
| Goats | Cows | Total | |
| Vaccinated | x/4 | (72-x)/9 | x/4 + (72-x)/9 |
| Not vaccinated | 3x/4 | 8(72-x)/9 | 3x/4 + 8(72-x)/9 |
| Total | x | 72-x | 72 |
Since all numbers in the table are integers, x/4 is an integer (72-x)/9 is also an integer
x=72-y is a multiple of 4, 72-x=y is a multiple of 9
| y | 9 | 18 | 27 | 36 | 45 | 54 | 63 | 36 is a multiple of 9 | |
| x=72-y | 63 | 54 | 45 | 36 | 27 | 18 | 9 | 36 is a multiple of 4 |
x = 36
| Goats | Cows | Total | |
| Vaccinated | 9 | 4 | 13 |
| Not vaccinated | 27 | 32 | 59 |
| Total | 36 | 36 | 72 |
SUFFICIENT
(2) The ratio of vaccinated goats to vaccinated cows is 9 to 4.
| Goats | Cows | Total | |
| Vaccinated | 9k | 4k | 13k |
| Not vaccinated | x-9k | 72-x-4k | 72-13k |
| Total | x | 72-x | 72 |
Case 1: k = 1
| Goats | Cows | Total | |
| Vaccinated | 9 | 4 | 13 |
| Not vaccinated | x-9 | 68-x | 59 |
| Total | x | 72-x | 72 |
Case 2: k = 2
| Goats | Cows | Total | |
| Vaccinated | 18 | 8 | 26 |
| Not vaccinated | x-18 | 64-x | 46 |
| Total | x | 72-x | 72 |
NOT SUFFICIENT
IMO A
