Q170
The arithmetic mean of the scores of a group of students in a test was 52. The brightest 20% of them secured a mean score of 80 and the dullest 25% a mean score of 31. The mean score of remaining 55% is-
A.
45
B.
50
C.
51.4 approx
AnswerD.
54.6 approx
Answer: Option C
Solution
Answer: Option C
Solution:
Let the required mean score be xThen,