Problem:
If your average score on your first six mathematics tests was and your average score on your first seven mathematics tests was , then your score on the seventh test was
Answer Choices:
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Solution:
To get an average of on tests, you needed a total of points. After tests, you had a total of points. Thus you needed points on the seventh test.
If was your score on the seventh test, then so .
To raise your average by one point, you needed seven additional points on the seventh test, so your score was .
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions