Question 823032: there are 100 students, the average score on tests is 76%, the boys average score is 80% the girls is 70%, how many girls are there?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! there are 100 students, the average score on tests is 76%, the boys average score is 80% the girls is 70%, how many girls are there?Equations:
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b + g = 100 students
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Total points on tests = 100(76) = 7600
Total boys points = 80b
Total girls points= 70g
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80b + 70g = 7600
b + g = 100
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Modify for elimination:
8b + 7g = 760
8b + 8g = 800
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Subtract and solve for "g":
g = 40 (# of girls)
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Cheers,
Stan H.
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