Problem Solving
posted by Carrie on .
Lindsey has 75% as her final grade, but after she writes her exam she gets 85%.
If her exam is worth 7.5%, what is her final grade.

Multiply 75 by 0.925.
Multiply 85 by 0.075.
Add the two products together to get her final grade. 
Don't you take 75x0.075= 6.375
then add that to her final grade of 75% to get 81.375? 
No, that's not correct.
75% is an average of all of the work that she did during the semester. 
Thanks but,I don't understand, because
75x0.925= 69.375
85x0.075= 6.375
69.375 + 6.375= 75
How can that be right? Where did you get 0.925 from. Isn't her final grade going to go up after her 85% on the exam. 
I got the 0.925 by subtracting 0.075 from 1.
By my calculations, the grade only goes up from 75 to 75.75. Rounded to the nearest percent = 75.75 = 76. A final grade of 76% makes sense because the exam is only a small part of the final grade.