A student is taking a class where $40\%$ of his or her grade is based on homework and the remaining $60\%$ is based on tests. There are a total of 12 homework assignments and 4 tests. The student completes $9/12$ assignments with a perfect score and all 4 tests with a perfect score. What is his final grade? I first converted the homework assignments into a decimal $$ 9/12 = .75 $$ since their homework is 40% of their grade: $$ .75 * .4 = .3$$ which I then added to the final quiz percentage to get a total grade for the class: $$ .3 + .6 = .9 $$ $$.9 * 100 = 90 $$
The student completed the class with an A(90%), however I'm not sure this calculation is correct. Can someone please verify?
You are correct. Another way to think about it is to have $100$ points available. Each test is $\frac 14$ of $60\%$ of $100$ or $15$ points. Each homework is $\frac 1{12}$ of $40\%$ of $100$ or $\frac {10}3$ points. The student has accumulated $4 \cdot 15 + 9 \cdot \frac {10}3=90$ points.