What is the overall average of these:
0 (represents 20%)
0.25 (represents 50%)
0.2 (represents 30%)

I know it's easy, my mind just went blank. ty

0.185 methinks.

0 * .2 = 0

0.25 * .5 = 0.125

0.2 * .3 = 0.06

so the sume is 0.185 as 'joeinfhills' stated

I put at that first but the average is too low in that method, it doesn't look right

100% = 1.0
10% = 0.10
1% = 0.01
0.1% = 0.001

Also, you can just pretend those percentages are a points system out of 100 points and use points. That's how I usually find my grade in courses.

Quizzes = 15% of grade
Homework = 10%
Exams = 50%
Final = 25%

Score a 90% on quizzes, a 85% on HW's, 35% on exams, 10% on final = 90(.15)+85(.1)+35(.5)+10(.25) = xxx/100 pts. (hypothetical situation, that would be a terrible grade lol, don't have a calculator atm) I think it's a 31.5 maybe? Idk but it's a good way to find your grade in a weighted class.