Students

**Cute** · 06-16-2005, 09:09 AM

X is the average height of a class and Y is average height of another class. What is the ratio of X/Y?

1. X=120
2. Average of X and Y is 126

**SOJO** · 06-16-2005, 10:45 AM

E)

Stmt 1 Insufficient

Stmt 2 Insufficient

Even after Combining 1 and 2 , we can not get value of Y to determine X/Y as we don’t know the number of students in each class .

**Priyadarshi** · 06-16-2005, 10:51 AM

Am i missing something here..the answer to me is a straightforward C.

Why do we need to know the no of students , the question stem is asking for the ratio between the two averages.

Stmt 1 : only X is known
Stmt 2 on its own insuff only an equation of X and Y known

combined we get the ratio

**arjmen** · 06-16-2005, 10:59 AM

I reckon C is correct

I: Don't know Y. Insuff
II: (X+Y)/2 = 126 (not the average of the classes combined but the average of the 2 averages). Not enough to get a ratio though. Insuff

I&II: X+Y=252 and X=120. Suff

**Cute** · 06-16-2005, 12:49 PM

E it is

**arjmen** · 06-16-2005, 01:53 PM

Originally Posted by Cute

X is the average height of a class and Y is average height of another class. What is the ratio of X/Y?
1. X=120
2. Average of X and Y is 126

I find the wording of statement II ambiguous.

I feel that there are 2 views that can be taken:

1) The statement 'average of X and Y' means the simple average of the values, X and Y
=> (X+Y)/2 = 126

2) The statement 'average of X and Y' means the average height of the combined class.
So if there are 'n' students in the first class and 'm' students in the other, then (nX+mY)/(n+m) = 126

This ambiguity has an effect on the answer. In the former case, the answer would be C and in the latter, it would be E.

Perhaps I'm not seeing the question correctly.

**sumeet_rana** · 06-16-2005, 03:35 PM

I think the questions is pretty straightforward. It is C as per the explanation given by most of u here.

What is the Official Answer ? That will determine to look at such questions in a simple way or to look deep as option 2 by arjmen

**rd_eastbay** · 06-16-2005, 10:05 PM

Arj - I think your original interpretation is correct. X and Y are just numbers and should be treated as such. IMHO they don't carry the implied meaning of "the average of the two classes".

**Adrionni** · 06-20-2005, 05:24 PM

I think that the answer is C. By combining the two statements, you'll find that the average height of students in class Y is 132, and can find out the ratio of X to Y...

**TheFighter** · 06-20-2005, 11:59 PM

Its C for me.
X = average of C1
Y = Average of C2
X = 120 - Insufficient ( Do not or cannot know about Y )
X+Y /2 = 126 ( Insufficient)

Both
X/Y = 120/132 (Trap X and Y average ( X+Y/2) = 126 ) Could this be a ERS trap???
One and Only answer 120/132

C it is.