Question

A math club took a math test. Twelve of the members had an average score of 80. Eighteen of the members had an average score of 86. what is was the class average

Answer 1

12 x 80 = 960
18 x 86 = 1548
960 + 1548 = 2508
12 + 18 = 30
2508/30 = 83.6

The class average is 83.6

Answer 2

Let’s add the percentages up.
There were twelve people who had an average of 80. With this, you just have to believe they all received an 80%. The same with the score of 86.
12•80=960
18•86=1,548
Now add them together.
960+1,548=2,508
Now add the total students.
12+18=30
2,508/30
83.6
The class average is 83.6%