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 all the positive multiples
[#permalink]
25 Apr 2017, 02:56
25 Apr 2017, 02:56
Expert Reply
00:00
Question Stats:
80% (00:46) correct
19% (00:39) wrong based on 223 sessions
Hide Show timer Statistics
Quantity A |
Quantity B |
The average (arithmetic mean) of all the positive multiples of 5 less than 26 |
The average (arithmetic mean) of all the positive multiples of 7 less than 26 |
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 all the positive multiples
[#permalink]
09 Oct 2017, 07:40
09 Oct 2017, 07:40
2
This question can be solved by computing the averages on quantity A, i.e. 5+10+15+20+25/5 = 15 and on quantity B, i.e. 7+14+21/3 = 14. Answer A.
To be even faster, one can notice that in evenly spaces sets the median and the mean coincide, so that we just have to write down the elements of each set and take the central one (since the number of elements is odd). This way we have to compare 15 and 14, thus answer A
To be even faster, one can notice that in evenly spaces sets the median and the mean coincide, so that we just have to write down the elements of each set and take the central one (since the number of elements is odd). This way we have to compare 15 and 14, thus answer A
Re: The average (arithmetic mean) of all the positive multiples
[#permalink]
02 Apr 2018, 12:14
02 Apr 2018, 12:14
1
Answer: A
A: Multiples of 5 less than 26 are: 5, 10, 15, 20, 25
As each of the values is result of a constant value to previous object in sequence, their average is: (a1 +an)/2 = (5 + 25) / 2 = 15
B: The positive multiples of 7 less than 26 are: 7, 14, 21
As each of the values is result of a constant value to previous object in sequence, their average is: (a1 +an)/2 = (7 + 21) / 2 = 14
A is bigger than B
A: Multiples of 5 less than 26 are: 5, 10, 15, 20, 25
As each of the values is result of a constant value to previous object in sequence, their average is: (a1 +an)/2 = (5 + 25) / 2 = 15
B: The positive multiples of 7 less than 26 are: 7, 14, 21
As each of the values is result of a constant value to previous object in sequence, their average is: (a1 +an)/2 = (7 + 21) / 2 = 14
A is bigger than B
