Problem:
Back in 1930, Tillie had to memorize her multiplication facts from through . The multiplication table she was given had rows and columns labeled with the factors, and the products formed the body of the table. To the nearest hundredth, what fraction of the numbers in the body of the table are odd?
Answer Choices:
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B.
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E.
Solution:
There are entries in the body of the table. An entry is odd if and only if both its row factor and its column factor are odd. There are 6 odd whole numbers between 0 and 12 , so there are odd entries in the body of the table. The required fraction is .
The problems on this page are the property of the MAA's American Mathematics Competitions