Verified answer

99 x.80 = 79.2

80 x. 20 = 16.0

95.2%

If you have already done the work that makes up 80% (= 0.80) of your final grade and you have earned a 99% on that work; and if you are about to take an exam worth 20% (= 0.20) of your final grade and earn an 80%, then your grade after the exam will be:

((0.80 * 99) + (0.20 * 80))/(0.80 + 0.20)

Do you see how I got those numbers from my first paragraph? You multiply the weight of each partial grade by the grade itself, add those numbers up, and divide by the total of all the weights.

Since, in this case, you will have completed all of the work for the class, the weights, 0.80 and 0.20, will add up to 1.00, you can ignore the denominator entirely, and your grade will be:

(0.80 * 99) + (0.20 * 80)

That is the same as:

79.2 + 16

which is, of course, equal to:

95.2

So your grade for the class will be 95.2%

in case you multiply the 30 and 50 by ability of two, you will see 60 out of a hundred, which ability to procure 60% on your attempt. 50% (or a million/2) of 20 is 10, mutually as 10% (or a million/10) is two. to procure 12% out of 20%.