Problem:
Isaac has written down one integer two times and another integer three times. The sum of the five numbers is 100 , and one of the numbers is 28 . What is the other number?
Answer Choices:
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Solution:
Let be the integer Isaac wrote two times, and let be the integer Isaac wrote three times. Then . If , then , and cannot be an integer. Therefore and , so .
The problems on this page are the property of the MAA's American Mathematics Competitions