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Is the average (arithmetic mean) of 5 different positive [#permalink ]
01 Apr 2006, 15:48
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Is the average (arithmetic mean) of 5 different positive integers at least 30?

(1) Each of the integers is a multiple of 10

(2) The sum of the 5 integers is 160

My question is, is 0 multiple of 10?

OPEN DISCUSSION OF THIS QUESTION IS HERE: is-the-average-arithmetic-mean-of-5-different-positive-132144.html
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Last edited by

Bunuel on 08 Jul 2013, 09:41, edited 1 time in total.

Moved to DS forum, renamed the topic, edited the question and added the OA.

VP

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Yeah 0 is a multiple of all numbers!

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I wud say that the answer is E!
Whats the oa?

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Re: Arithmetic mean [#permalink ]
01 Apr 2006, 17:43

bewakoof wrote:

Is the average (arithmetic mean) of 5 different positive integers atleast 30? 1. Each of the integers is a multiple of 10. 2. The sum of 5 integers is 160. My question is, is 0 multiple of 10?

0 is multiple of all numbers but is not +ve. so we cannot consider it as a +ve multiple of 10 here.

D.

from i, the sum of the five different integers is 150. so the ave is at least 30. suff

from ii, if the sum of 5 numbers is 160, then their average is more than 30. suff.

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agreed! Missed the +ve Part

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i also agree with D ... but good rule about 0 i had a DS where that was tested

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Thanks.. missed the positive integer part.. thought 0 was the multiple and chose B..

OA is D..

btw. prof.. you rock!!

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Agree with (D).
he fact that 0 is a multiple of all integers will most likely not be tested on the GMAT.

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This is where thye potentially test for 0 as a multiple of a number

http://www.gmatclub.com/phpbb/viewtopic ... 284#187284

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What I meant was that, they do have problems where they use test:

'0 as a multiple of a number'

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Re: Arithmetic mean [#permalink ]
24 Apr 2007, 23:34

Why do we say that -

Professor wrote:

from i, the sum of the five different integers is 150. so the ave is at least 30. suff

10 is also multiple of 10. So the minimum will be 10+10+10+10+10 = 50... How do we get 150?

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Re: Arithmetic mean [#permalink ]
24 Apr 2007, 23:37

nick_sun wrote:

Why do we say that -

Professor wrote:

from i, the sum of the five different integers is 150. so the ave is at least 30. suff

10 is also multiple of 10. So the minimum will be 10+10+10+10+10 = 50... How do we get 150?

"5

different positive integers "....least could be 10, 20, 30, 40, 50

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Re: Arithmetic mean [#permalink ]
24 Apr 2007, 23:58

Juaz wrote:

nick_sun wrote:

Why do we say that -

Professor wrote:

from i, the sum of the five different integers is 150. so the ave is at least 30. suff

10 is also multiple of 10. So the minimum will be 10+10+10+10+10 = 50... How do we get 150?

"5

different positive integers "....least could be 10, 20, 30, 40, 50

Oh, gosh! It is my silliest mistake

Thank you Juaz!

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yep its D.
Javed.
Cheers!

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St1:
If the 5 integers are 10,20,30,40 and 50, then ave = 30. Since this is the smallest valid set of integers, so st1 is sufficient.
St2:
The average is alwasy 32. St2 is sufficient.
Ans D

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I made the mistake of "at least", being different than "greater than"
Where at least means >= 30
But greater than means > 30
Crap!

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Re: Arithmetic mean [#permalink ]
13 Oct 2007, 23:00

bewakoof wrote:

Is the average(arithmetic mean) of 5 different positive integers atleast 30? 1. Each of the integers is a multiple of 10. 2. The sum of 5 integers is 160. My question is, is 0 multiple of 10?

D,

Sum >=150 ?

1) Min possible sum: 10+20+30+40+50=150 or more SUFF

2) 160 is more than 150. SUFF.

D.

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Re: Is the average(arithmetic mean) of 5 different positive [#permalink ]
08 Jul 2013, 09:26

This answer should be a B anyone get this OA yet? and bewa.. yes it is an integer and multiplied by tself it is the multiple of any integer incl 10 bu tthen the sum is already given, which boundary are you trying to fathom?

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Re: Is the average(arithmetic mean) of 5 different positive [#permalink ]
08 Jul 2013, 09:43
docdrizzeally wrote:

This answer should be a B anyone get this OA yet? and bewa.. yes it is an integer and multiplied by tself it is the multiple of any integer incl 10 bu tthen the sum is already given, which boundary are you trying to fathom?

Is the average (arithmetic mean) of 5 different positive integers at least 30? It's almost always better to express the average in terms of the sum. The question basically asks whether the sum of 5

different positive integers is at least 5*30=150.

(1) Each of the integers is a multiple of 10 --> the least values of these 5

different positive integers are: 10, 20, 30, 40, and 50 --> the sum = 150. Sufficient.

(2) The sum of the 5 integers is 160. Directly answers the question. Sufficient.

Answer: D.

OPEN DISCUSSION OF THIS QUESTION IS HERE: is-the-average-arithmetic-mean-of-5-different-positive-132144.html In case of any questions please post in that thread. This topic is locked.

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Re: Is the average(arithmetic mean) of 5 different positive
[#permalink ]
08 Jul 2013, 09:43