GRE Prep 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.
The average (arithmetic mean) of x and y
[#permalink]
19 May 2017, 01:18
19 May 2017, 01:18
Expert Reply
3
Bookmarks
00:00
A
B
C
D
Question Stats:
71% (00:49) correct
28% (00:53) wrong based on 218 sessions
Show timer Statistics
x<y
Quantity A |
Quantity B |
The average (arithmetic mean) of x and y |
The average (arithmetic mean) of x, y and y |
A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Given Kudos: 136
Re: x < y
[#permalink]
18 Sep 2017, 14:19
18 Sep 2017, 14:19
5
Carcass wrote:
x < y
Quantity A |
Quantity B |
The average (arithmetic mean) of x and y |
The average (arithmetic mean) of x, y and y |
We can solve the question using matching operations
First apply the formula for finding averages
Quantity A: (x + y)/2
Quantity B: (x + y + y)/3
Simplify Quantity B to get:
Quantity A: (x + y)/2
Quantity B: (x + 2y)/3
Eliminate that fractions by multiplying both quantities by 6 (the least common multiple of 2 and 3)
When we do this, we get:
Quantity A: 3(x + y)
Quantity B: 2(x + 2y)
Expand to get:
Quantity A: 3x + 3y
Quantity B: 2x + 4y
Subtract 2x from both quantities to get:
Quantity A: x + 3y
Quantity B: 4y
Subtract 3y from both quantities to get:
Quantity A: x
Quantity B: y
Since we're told that x < y, we can conclude that Quantity B is greater.
Answer:
Show: ::
B
RELATED VIDEOS FROM OUR COURSE
General Discussion
Re: x < y
[#permalink]
17 Sep 2017, 01:24
17 Sep 2017, 01:24
2
How could the answer be B? Without any restriction about the values of x and y, they could also be both equal to zero and then A and B would be equal. Otherwise, if for example x = 1 and y = 2, then column A would be 3/2, while column B would be 5/2, thus column B would be greater. Since there is no unique relationship, the answer should be D!
