SOLUTION: The day of a quiz, only Michelle was absent. The average grade of the other students was 85. When Michelle took a make-up quiz her grade was a 30 which lowered the class average to
Algebra.Com
Question 644499: The day of a quiz, only Michelle was absent. The average grade of the other students was 85. When Michelle took a make-up quiz her grade was a 30 which lowered the class average to 80. How many students are in the class?
Found 2 solutions by jim_thompson5910, Alan3354:
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
(30+85n)/(n+1) = 80
30+85n = 80(n+1)
30+85n = 80n+80
85n-80n = 80-30
5n = 50
n = 50/5
n = 10
So there are 10+1 = 11 students in the class.
--------------------------------------------------------------------------------------------------------------
If you need more help, email me at jim_thompson5910@hotmail.com
Also, please consider visiting my website: http://www.freewebs.com/jimthompson5910/home.html and making a donation. Thank you
Jim
--------------------------------------------------------------------------------------------------------------
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
The day of a quiz, only Michelle was absent. The average grade of the other students was 85. When Michelle took a make-up quiz her grade was a 30 which lowered the class average to 80. How many students are in the class?
-----------------------
n = # of others
(n*85 + 30)/(n+1) = 80
85n + 30 = 80n + 80
5n = 50
n = 10 others, + Michelle = 11 students
RELATED QUESTIONS
The day of a quiz, only Michelle was absent. The average grade of the other students was... (answered by ankor@dixie-net.com)
The average (arithmetic mean) grade of 2 students on a geometry quiz was 82. The average... (answered by ikleyn)
Hi
Tim and Michelle drove from A to B which was 285km away. Tim set off for B at an... (answered by CPhill,greenestamps,MathTherapy)
Twenty students took their Chemistry test on Tuesday and their average (arithmetic mean)... (answered by stanbon)
James and Vanessa were absent for the day of a test. When they returned and took the... (answered by MathTherapy)
Twelve students took a math exam and obtained an average score of 80%. If four students... (answered by josmiceli,greenestamps,josgarithmetic)
The school has ten classes with the same amount of students in each class. One day the... (answered by ptaylor)
A group pupil took part in a quiz and scored an average of 38 marks, when one of the... (answered by MathTherapy)
What fraction of the number of chicken pies baked by michelle was the number of chicken... (answered by ikleyn)