I'll give you a question, please answer with step-by-step reasoning process.
A class is 40% boys. The rest are girls. Every boy in class gets an 80% on the math test. Every girl gets a 90%. What is the class average on the test?

86
The class is 60% girls because 100 - 40 = 60.

The class average is 86% because.

4(80) +.

6(90) = 86.

.

So, the final answer is 86