Arithmetic Mean Doubt

[goelmohit2002]

Hi All,

I will post OA after some discussion...so that other fellow members reasoning is not biased by OA.

The results of a certain experiment included 6 data values that were all multiples of the same number c, namely, c, 8c, 2c, 5c, 4c, and 4c. Was the average (arithmetic mean) of the 6 data values greater than 8?
(1) c < 4
(2) c > 2

Thanks
Mohit

[scoobydooby]

AM: (c+8c+2c+5c+4c+4c)/6=24c/6=4c

1) c<4
if c=3, AM=4*3=12 > 8
if c-1, AM=4*1=4 <8
not sufficient

2) c>2
if c=2, AM=4*2=8
so if c>2, AM >8
sufficient

hence B

[goelmohit2002]

yes got it....i made a calculation mistake of dividing by 8...while calculating average...

Yes the OA is "B".

[goelmohit2002]

Can someone please help me in resolving one small doubt?

The above statement says: "all multiples of the same number c".

can we assume by this statement that "c" is integer....or there can be multiples of real number too.

[Ian Stewart]

Can someone please help me in resolving one small doubt?

The above statement says: "all multiples of the same number c".

can we assume by this statement that "c" is integer....or there can be multiples of real number too.

We typically only use the term 'multiple' when dealing with integers. In a real GMAT question, this would normally be stated explicitly - were the question in the original post above a real GMAT question, I'd expect it to say that c is an integer.

[goelmohit2002]

I am not sure whether this is a real GMAT question....but this is one of the VIP tests question....