Problem:
Suppose July of year has five Mondays. Which of the following must occur five times in August of year ? (Note: Both months have 31 days.)
Answer Choices:
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B.
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E.
Solution:
Since July has 31 days, Monday must be one of the last three days of July. Therefore, Thursday must be one of the first three days of August, which also has 31 days. So must occur five times in August.
The problems on this page are the property of the MAA's American Mathematics Competitions