Arith Mean

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Arith Mean

by abhirup1711 » Thu Jan 16, 2014 4:01 am
Is the AM of 5 different +ve integers atleast 30?
a. Each of the integers is a multiple of 10
b. The sum of the 5 integers is 160

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by Uva@90 » Thu Jan 16, 2014 5:45 am
abhirup1711 wrote:Is the AM of 5 different +ve integers atleast 30?
a. Each of the integers is a multiple of 10
b. The sum of the 5 integers is 160
Hi Abhirup1711,

We need to find: is AM of 5 different positive integers at least 30 (Yes/No Question)

Statement 1: Each of the integers is a multiple of 10
let us go for least values,
10,20,30,40,50
So now Am is 150/5 = 30
Yes. Sufficient.

Statement 2:
The sum of the 5 integers is 160

160/5 = 32 >30
hence Yes. Sufficient.

Answer is D

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Uva.
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by Brent@GMATPrepNow » Sun Jan 26, 2014 11:01 am
abhirup1711 wrote:Is the AM of 5 different +ve integers atleast 30?
a. Each of the integers is a multiple of 10
b. The sum of the 5 integers is 160
Uva's solution is great.

I just wanted to point out that the word "different" is the key word in this question. If we fail to see that word, we'll incorrectly conclude that the answer is B.
I mention this because failing to notice a particular word (e.g., different, integer, positive, etc) is one of the most popular sources of silly errors on the GMAT.

If anyone is interested, I recently wrote an article about avoiding silly errors: https://www.beatthegmat.com/mba/2012/09/ ... n-the-gmat

Cheers,
Brent
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by Brent@GMATPrepNow » Sun Jan 26, 2014 11:13 am
abhirup1711 wrote:Is the AM of 5 different +ve integers atleast 30?
a. Each of the integers is a multiple of 10
b. The sum of the 5 integers is 160
If anyone is wondering, "AM" stands for Arithmetic Mean.
I should point out that the GMAT doesn't expect you to know this. For questions involving "AM," the GMAT typically uses the term "Average" with "Arithmetic Mean" in brackets, as in:
"... x is the average (arithmetic mean) of set K...

Cheers,
Brent
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