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6. A perfect number is a positive integer that is equal to the sum of its proper positive
factors. Proper positive factors of a number are positive factors that are less than
the number. For example, 6 = 1 + 2 + 3 is a perfect number because 1, 2 and 3
are the only proper positive factors of 6. Find the next perfect number.
7. If a and b are positive whole numbers such that a < b and a^b = b^a, find apossible value for a and for b.
9. What are the last 5 digits of the sum 1 + 11 + 111 + ... + 111...111(2014 digits)?
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