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#### Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here. # Integers a and b are consecutive multiples of 6. Integers x  Question banks Downloads My Bookmarks Reviews Important topics
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GRE Prep Club Legend  Joined: 07 Jun 2014
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Integers a and b are consecutive multiples of 6. Integers x [#permalink]
Expert's post 00:00

Question Stats: 22% (00:51) correct 77% (00:53) wrong based on 22 sessions
Integers a and b are consecutive multiples of 6. Integers x and y are consecutive multiples of 8. In terms of a, b, x, and y, what is the ratio of the average of a and b and the average of x and y?

A. $$\frac{(x+y)}{(a+b)}$$
B. $$\frac{(a+b)}{(x+y)}$$
C. $$(a+\frac{b}{4})/(y-\frac{x}{4})$$
D. $$(a+\frac{b}{4})/(y-\frac{x}{2})$$
E. $$\frac{1}{2}\frac{(a+b)}{(x+y)}$$

Drill 4
Question: 8
Page: 294
[Reveal] Spoiler: OA
GRE Prep Club Legend  Joined: 07 Jun 2014
Posts: 4857
GRE 1: Q167 V156 WE: Business Development (Energy and Utilities)
Followers: 105

Kudos [?]: 1776 , given: 397

Re: Integers a and b are consecutive multiples of 6. Integers x [#permalink]
Expert's post
Explanation

You should Plug In on this question. Variables a and b can be consecutive numbers such as 6 and 12. Plug in consecutive multiples of 8 for x and y, such as 8 and 16. Finding the ratio of the averages is easy now; the averages of each pair of numbers will be the halfway point between the two numbers. For 6 and 12, the average is 9. For 8 and 16, the average is 12.

The ratio of these averages is $$\frac{3}{4}$$. Now, plug your original numbers into the answer choices and
look for the one that equals $$\frac{3}{4}$$. Choice (A) gives you $$\frac{4}{3}$$, which is the reciprocal of what you want. Cross it off. Choice (B) gives you $$\frac{3}{4}$$which is what you’re looking for. But don’t stop yet—keep checking all of the answers. Choice (D) also works with these numbers. No harm done, just try a different set of numbers and check the two remaining choices.

Plug in some really unusual numbers, like 24 and 30 for a and b, and 80 and 88 for x and y. Now you are looking for an answer to give you $$\frac{9}{28}$$ Choice (B) no longer works, so choice (D) is your answer.

Hence option D is the only correct option.
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Intern Joined: 07 Aug 2016
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Re: Integers a and b are consecutive multiples of 6. Integers x [#permalink]
sandy could you define this approach? how can we be sure that substitution method is to be applied for this question and not solving it through algebraic method?
GRE Prep Club Legend  Joined: 07 Jun 2014
Posts: 4857
GRE 1: Q167 V156 WE: Business Development (Energy and Utilities)
Followers: 105

Kudos [?]: 1776 , given: 397

Re: Integers a and b are consecutive multiples of 6. Integers x [#permalink]
Expert's post
shikha0611 wrote:
sandy could you define this approach? how can we be sure that substitution method is to be applied for this question and not solving it through algebraic method?

Algebraic method takes time. And time is something you will not have on the GRE. So substitution is the best option in this case.
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Intern Joined: 25 Dec 2016
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Re: Integers a and b are consecutive multiples of 6. Integers x [#permalink]
I could not understand your post sandy.Please explain.
GRE Prep Club Legend  Joined: 07 Jun 2014
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GRE 1: Q167 V156 WE: Business Development (Energy and Utilities)
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Kudos [?]: 1776 , given: 397

Re: Integers a and b are consecutive multiples of 6. Integers x [#permalink]
Expert's post
Snehg wrote:
I could not understand your post sandy.Please explain.

Put value 6 and 12 for $$a$$ and $$b$$; and 8 and 16 for $$x$$ and $$y$$. See which options hold.

Then put value 30 and 36 for $$a$$ and $$b$$; and 40 and 48 for $$x$$ and $$y$$. To validate your answer.
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Manager Joined: 27 Sep 2017
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Re: Integers a and b are consecutive multiples of 6. Integers x [#permalink]
sandy wrote:
Snehg wrote:
I could not understand your post sandy.Please explain.

Put value 6 and 12 for $$a$$ and $$b$$; and 8 and 16 for $$x$$ and $$y$$. See which options hold.

Then put value 30 and 36 for $$a$$ and $$b$$; and 40 and 48 for $$x$$ and $$y$$. To validate your answer.

i think you are wrong, answer is B, I plug number you provide B is answer
GRE Prep Club Legend  Joined: 07 Jun 2014
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GRE 1: Q167 V156 WE: Business Development (Energy and Utilities)
Followers: 105

Kudos [?]: 1776 , given: 397

Re: Integers a and b are consecutive multiples of 6. Integers x [#permalink]
Expert's post
Peter wrote:
i think you are wrong, answer is B, I plug number you provide B is answer

You are correct! Answer is B and the official explanation is super wrong!

Fixed it! Thanks
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Re: Integers a and b are consecutive multiples of 6. Integers x [#permalink]
sandy wrote:
Peter wrote:
i think you are wrong, answer is B, I plug number you provide B is answer

You are correct! Answer is B and the official explanation is super wrong!

Fixed it! Thanks

Yeah i got B too Intern Joined: 30 Aug 2018
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Re: Integers a and b are consecutive multiples of 6. Integers x [#permalink]
What is the final correct ans ? B or D? GRE Prep Club Legend  Joined: 07 Jun 2014
Posts: 4857
GRE 1: Q167 V156 WE: Business Development (Energy and Utilities)
Followers: 105

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Re: Integers a and b are consecutive multiples of 6. Integers x [#permalink]
1
KUDOS
Expert's post
Aroma wrote:
What is the final correct ans ? B or D?

It is B
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Try our free Online GRE Test Re: Integers a and b are consecutive multiples of 6. Integers x   [#permalink] 06 Oct 2018, 06:30
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