SOLUTION: Josh wants to learn a minimum grade of an 85 this semester in algebra. His test and class work on average is an 82, this grade will count as 80% of his semester grade. His exam wil

Josh wants to learn a minimum grade of an 85 this semester in algebra. His test and class work on average is an 82, this grade will count as 80% of his semester grade. His exam will be worth 100 points and will count as 20% of his total grade. Write and solve an inequality to determine what minimum grade Josh must make on his exam to earn an 85/B for his final grade. 
Ans:
Say he scores x/100 in the final exam.
The class work score of 82/100 carries 80% weightage. The final exam score (x/100)
will carry 20% weightage.
This is similar to saying that the final score is the sum of the scores in 2 tests
- class work test of 80 marks and final exam of 20 marks.
The overall grade of 85 is the sum of 2 scores:
1) Class work score with 80% weightage = 82 * 80* = 65.6. In other words, 
scoring 82/100 in the class test is the same as scoring 65.6/80 in the final
grade.
2) Final exam score with 20% weightage = (x)*20% = 0.2*x. In other words, 
scoring x/100 in the final test is the same as scoring 0.2*x in the final
grade.
Now the final grade is the sum of the 2, and has to be at least 85.
So you have the inequality

Simplifying
 or 
He has to score at least 97/100 or higher in the final exam to get an overall
grade of 85.
Hope you got it :)