Category: Algebra
"Published in Newark, California, USA"
Lilian's average in 3 quizzes is 80%. If she made 5% more in the first than in the second and 8% less in the third, what grades did she get in the three quizzes?
Solution:
The given item in a word problem is the average of the three quizzes of Lilian with conditions of her quizzes and we have to find the grades of her quizzes as follows
Let x = the score of her 2nd quiz
x + 5% = the score of her 1st quiz
x - 8% = the score of her 3rd quiz
Average of three quizzes = ⅓(1st Quiz + 2nd Quiz + 3rd Quiz)
80% = ⅓ (x + 5% + x + x - 8%)
3x - 3% = 240%
3x = 240% + 3%
3x = 243%
x = 81%
Therefore
Lilian's grade in 1st Quiz = x + 5% = 81% + 5% = 86%
Lilian's grade in 2nd Quiz = x = 81%
Lilian's grade in 3rd Quiz = x - 8% = 81% - 8% = 73%
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