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, y, and z
[#permalink]
30 Aug 2018, 07:29
30 Aug 2018, 07:29
3
Expert Reply
9
Bookmarks
00:00
Question Stats:
47% (00:51) correct
52% (00:40) wrong based on 140 sessions
Hide Show timer Statistics
Quantity A |
Quantity B |
The average (arithmetic mean) of x, y, and z |
The average (arithmetic mean) of 0.5x, 0.5y, and 0.5z |
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.
Re: The average (arithmetic mean) of x, y, and z
[#permalink]
15 Oct 2018, 09:08
15 Oct 2018, 09:08
1
Answer is (D). The average of x, y, and z is . Calculated similarly, the average of 0.5x, 0.5y, and
0.5z is exactly half that. If the sum of the variables is positive, Quantity A is greater. However, if the
sum of the variables is negative, Quantity B is greater. If the sum of the variables is zero, the two
quantities are equal.
0.5z is exactly half that. If the sum of the variables is positive, Quantity A is greater. However, if the
sum of the variables is negative, Quantity B is greater. If the sum of the variables is zero, the two
quantities are equal.
Re: The average (arithmetic mean) of x, y, and z
[#permalink]
13 Jan 2019, 22:49
13 Jan 2019, 22:49
Expert Reply
plug in 10, 20,30
(10+20+30)/3= 60/3= 20
do the same for Quantity B and we get
(5+10+15)/3= 30/3 =10
So here, quantity A looks greater
then plug in the negative versions for Quantity A
(-10+-20+-30)/3= -20
Plug in the negative versions for Quantity B
(-5+-10+-15)/3= -10
-10 is greater than -20, which is the opposite of when the numbers are positive.
since A is greater when the numbers are positive, and B is greater when the numbers are negative,
we have an inconsistent solution, and choose D
(10+20+30)/3= 60/3= 20
do the same for Quantity B and we get
(5+10+15)/3= 30/3 =10
So here, quantity A looks greater
then plug in the negative versions for Quantity A
(-10+-20+-30)/3= -20
Plug in the negative versions for Quantity B
(-5+-10+-15)/3= -10
-10 is greater than -20, which is the opposite of when the numbers are positive.
since A is greater when the numbers are positive, and B is greater when the numbers are negative,
we have an inconsistent solution, and choose D
