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Bunuel
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Is the average (arithmetic mean) of m and n less than 50? 27 Sep 2015, 12:08
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A
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

5% (low)

Question Stats:

91% (00:54) correct 9% (01:17) wrong based on 122 sessions

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Is the average (arithmetic mean) of m and n less than 50?

(1) The average (arithmetic mean) of 3m and 3n is 90
(2) m=n

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A
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Is the average (arithmetic mean) of m and n less than 50? 27 Sep 2015, 14:10
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Bunuel
Is the average (arithmetic mean) of m and n less than 50?

(1) The average (arithmetic mean) of 3m and 3n is 90
(2) m=n

Kudos for a correct solution.

Statement 1:
The average (arithmetic mean) of 3m and 3n is 90
or \(\frac{3m+3n}{2}=90\)
or \(\frac{m+n}{2}=30\)
So, the average of m and n is less than 50
SUFFICIENT

Statement 2:
m=n
m and n can be any numbers.
So their average can be more or less than 50
INSUFFICIENT

Answer:-A
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Is the average (arithmetic mean) of m and n less than 50? 27 Sep 2015, 19:32
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Answer should be A,
statement 1 says,
(3m+3n)/2 = 90, -> (3/2)(m+n)=90, -> m+n = 90*2/3 = 60, hence m+n/2 = 30 which is less than 50
statement 2 says,
m = n by this at max we can say mean is either equal to m or n,
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Is the average (arithmetic mean) of m and n less than 50? Updated on: 28 Sep 2015, 09:15
Originally posted by AkshdeepS on 27 Sep 2015, 22:10.
Last edited by AkshdeepS on 28 Sep 2015, 09:15, edited 1 time in total.
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Bunuel
Is the average (arithmetic mean) of m and n less than 50?

(1) The average (arithmetic mean) of 3m and 3n is 90
(2) m=n

Kudos for a correct solution.


My Solution:

Stem: Is (m+n)/2<50

Then the question becomes: Is m+n<50*2 or Is m+n<100??

St 1) (3m+3n)/2=90 or 3m+3n=180 or m+n=60. Sufficient 60<100. Answer to the question is "yes"

St 2) m=n Not Sufficient as m and n can take any value.

[b]Thus, the answer is A[/b]
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Is the average (arithmetic mean) of m and n less than 50? 28 Sep 2015, 07:10
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I believe the answer is A. Please see below for explanation.

0) We are asked if (M+N)/2 < 50

1) We are told that (3M+3N)/2 = 90 which we can infer that

3(M+N)/2 = 90
(M+N)/2 = 30

if (M+N)/2=30 then it is less than 50. Sufficient

2) We are told that M=N

if M = 100 then N= 100 then (M+N)/2 would be 100 which is greater than 50

but M=20 then N=20 then (M+N)/2 would be 20 which is less than 50

Since the result can be either greater than 50 or less than 50 it is insufficient.

Answer A
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Is the average (arithmetic mean) of m and n less than 50? 21 Dec 2016, 20:50
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Nice Question.
Here is what i did in this one =>

Using =>


\(Mean =\frac{Sum}{#}\)


Mean = \(\frac{m+n}{2}\)
As per Question =>\(\frac{m+n}{2}<50\)
Hence \(m+n<100\)

Statement 1->
\(3m+3n=90*2\)
Hence \(m+n=60\)
Sufficient

Statement 2=>

Lets use test cases =>
1,1=> YES

101,101 => NO

Hence not sufficient

Hence A
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