Interesting DS Qn

[gmattering]

A group of consecutive integers, and the lowest number is 3. How many numbers are in the set?
(1) the average mean is 6 ;
(2) the range = average mean

I am getting it as (A)...

[Gmatters]

C is the answer

1) 36/6, 72/12
insuff

2) range= mean
insuff

combine:
mean=6
range=9-3

verify, 3+4+5+...9=42
42/7=6

[JustMe123]

D because 2) is sufficient by itself.

Let x be the highest number in the set. Then,
range = x-3 = (x+3)/2 since the midpoint is the mean.
2x-6 = x+3 --> x = 9 --> the set = {3, 4, 5, 6, 7, 8, 9}

[vijay vishnu]

Ans D .
1) Range = Mean = 6
If 3 is lowest , then avg >3.
3 is 3 short of mean 6
4 is 2 short of mean 6 , going like this , for the series to have a mean 6, there should be elements starting 3 ,4,5 ....9.

2) Range = Avg mean .
I guess this leaves with same information.

[gmattering]

vijay:

Stmt 2:these can be the elemnts of the set:
3,4,5,6,7,8,9 - here mean = range
3,4,5,6,7,8,9,10,11 - here also mean=range=7
and so on,so we don't know the exact number of elements in the set,

Stmt 1: says,mean is 6,only possible values of the set has to be:

3,4,5,6,7,8,9 i.e 7 elements

So i still feel,ans is A

[JustMe123]

range = the highest number - the lowest number
11 - 3 = 8 not 7

[Gmatters]

oh ya ...consecutive!

[gmattering]

oh yeah,D it is.Thanks "JustMe123",thy explanation was good.