Data Sufficiency

Professor Vasquez gave a quiz to two classes. Was the range of scores fro the first class equal to the range of scores for the second class?
(1) In each class, the number of students taking the quiz was 26, and the lowest score in each class was 70.
(2) IN each class, the average (arithmetic mean) score on the quiz was 85

(A) Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
(B) Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
(C) BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
(D) EACH statement ALONE is sufficient.
(E) Statements (1) and (2) TOGETHER are NOT sufficient.

I would choose E.

range= highest score - lowest score

statement 1:

Lack of highest score from class 1 and class 2.

Statement 2:

same problem as statement 1.


Please correct me if I made a mistake.

1. we know no of students in the class and lowest score

2. we know Avg of each class

from 1 and 2 together,we can just get total score of all the students and nothing else

None of the statement individually or together can give required info about Highest score as the Range may be calculated

Hence E

another (E)

We know 1 and 2 independently are insufficient.
So lets look at them together.

** I am not sure of this logic ** (is the idiom 'sure about' or ' sure of ')

We know that 70 is the lowest in each class and we know mean is 85.
So the highest should be 85 + (85-75) = 100 if the mean should remain at
85. The other 24 numbers should be between these such that none of them is less than 70. Coz if any number is less than 70, there should be a number > 100 to get the mean back to 85. From this I conclude,
answer is C.

I pictured this problem as a see-saw with 13 kids sitting on each side, the fulcrum is at 85 and a 70lb kid on one side.



Either I am wrong or I am smoking something !!
Thanks
-V

Agree with C

highest score = 100
range 100-70=30

What is OA?

I would go with C.

85=(70+X)/2
X=100

If I am not mistaken the OA is[spoiler] E) [/spoiler]bu we will wait for Carzy4gmat's confirmation since he posted the question.

Hence if u see my posts I always request users to post OA's using SPOILER. This way we dont have to keep waiting wihtout knowing the correct answer. Just a thought...

I checked and its a GMAT SETS question.

The OA is [spoiler]E)[/spoiler]

Dude..No MON NO FUN!

Give us the OA, we have the SOLUTION okay!!

Cramya is nice guy but I am not! SO MOVE SLOW and HAND US THE OA!

8)

Don't worry guys, I am in charge!

Feel free to jump in on this thought but even with statements 1 and 2 there is no way to tell if the range is the same or not. It may or may not be


26*85 - 70 makes up the remaining 25 scores. The highest value can be different for 2 classes and still the average could end up being 85. We dont know and cannot point to a single determinable value for the highest score, hence INSUFF

Eg:

Let say 1 is the lowest score for 2 classes with 5 studentsand the average 2

1 1 2 3 5
1 2 2 2 3

Clearly the lowest score is 1 for both class, 2 the mean but range for class 1 is different from range for class 2

(OR)

1 2 2 2 3
1 2 2 2 3

1 LOWEST SCORE, 2 MEAN RANGE SAME.

(1) In each class, the number of students taking the quiz was 26, and the lowest score in each class was 70.
(2) IN each class, the average (arithmetic mean) score on the quiz was 85

ya I have to go with E

For example,
The highest value could be 86.
To balance of the 70 score,
we could have 15 86 scores.
The rest could be exactly at the mean.

The highest value could also be 100.
To balance of the 70 score,
we could have 1 100 score.
The rest could be exactly at the mean.

Thus,
we can't know the range from the info given.

Eg:

Let say 1 is the lowest score for 2 classes with 5 studentsand the average 2

1 1 2 3 5
1 2 2 2 3

Clearly the lowest score is 1 for both class, 2 the mean but range for class 1 is different from range for class 2

(OR)

1 2 2 2 3
1 2 2 2 3

1 LOWEST SCORE, 2 MEAN RANGE SAME.

Are you sure 2 is the mean for the 1st group?

Fab, sorry that was a typo on my part

I was just picking some numbers to try to prove E)

here u go

Let say 1 is the lowest score for 2 classes with 5 studentsand the average 2

1 1 1 2 5
1 2 2 2 3