2021 AMC 12B Problems/Problem 4
Revision as of 18:39, 11 February 2021 by Sugar rush (talk | contribs)
Problem
Ms. Blackwell gives an exam to two classes. The mean of the scores of the students in the morning class is , and the afternoon class's mean score is
. The ratio of the number of students in the morning class to the number of students in the afternoon class is
. What is the mean of the scores of all the students?
Solution
WLOG assume there students in the morning class and
in the afternoon class. Then the average is