Question

There are 10 students in Class 1 and 40 students in Class 2.

All 50 students sit a test.
The mean score for the students in Class 1 was 80%
The mean score for the students in Class 2 was 70%
Find the mean score of all the students.

Answer 1

72%

Explanation:

We have 10 sudents in class 1 and 40 in the other for a total of 50 students.

The 10 in class 1 had a mean of 80 so we do 80x10=800

The mean of the class of 40 is 70, so we do 40x70=2800

we add both of those together to get 3600 then we divide that by 50 because there are 50 students in total.

3600/50=72.