Hi didieravoaka,
This question can be solved conceptually or by TESTing VALUES.
We're asked if the range of scores for one class equals the range of scores for a second class. This is a YES/NO question.
1) In each class, the number of students taking the quiz was 26, and the lowest score in each class was 70.
This tells us NOTHING about the ranges.
IF...
ALL the scores in the 1st class are 70 and ALL of the scores in the 2nd class are 70, then the answer to the question is YES.
ALL the scores in the 1st class are 70, but 25 of the scores in the 2nd class are 70 and 1 of the scores is a 71, then the answer to the question is NO.
Fact 1 is INSUFFICIENT
2) In each class, the average (arithmetic mean) score on the quiz was 85
This tells us NOTHING about the ranges.
IF...
ALL the scores in the 1st class are 85 and ALL of the scores in the 2nd class are 85, then the answer to the question is YES.
ALL the scores in the 1st class are 85, but HALF of the scores in the 2nd class are 80 and HALF of the scores is a 90, then the answer to the question is NO.
Fact 2 is INSUFFICIENT
Combined, we know...
In each class, the number of students taking the quiz was 26, and the lowest score in each class was 70.
In each class, the average (arithmetic mean) score on the quiz was 85
IF....
HALF the scores in the 1st class are 70 and HALF of the scores are 100 AND HALF of the scores in the 2nd class are 70 and HALF of the scores is a 100, then the answer to the question is YES.
HALF the scores in the 1st class are 70 and HALF of the scores are 100 AND 1/4 of the scores in the 2nd class are 70 and 3/4 of the scores are 90, then the answer to the question is NO.
Combined, INSUFFICIENT
Final Answer: E
GMAT assassins aren't born, they're made,
Rich
