raj44 wrote:2. The marks scored by 50 students of a class are m1, m2, m3 ...m50 where m1<m2<....m50. Student 1 scored 40 and student 50 scored 90. What is the average score of the class?
1. No two students scored the same marks and m25=62
2. The marks of the students follow an arithmetic progression.
OAB
Statement 1:
Since marks m₂...m₂₄ and m₂₆...m₄₉ are not known, the average of the 50 marks cannot be determined.
INSUFFICIENT.
Statement 2:
In an arithmetic progression, the distance between successive terms is a CONSTANT.
The result is that the values are EVENLY SPACED.
For any evenly spaced set, average = (biggest term + smallest term)/2.
Thus, the average of the 50 marks = (90+40)/2 = 65.
SUFFICIENT.
The correct answer is
B.
This DS is not reflective of an actual GMAT problem.
The GMAT does not expect us to know the definition of the term
arithmetic progression.
What is the source of this problem?
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