What is the positive integer n?
(1) The sum of all of the positive factors of n that are less than n is equal to n
(2) n < 30
OA E
Source: Manhattan Prep
What is the positive integer n?
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Global Stats
Numbers that satisfy Statement 1 are known as "perfect numbers" in math. You certainly don't need to know anything about "perfect numbers" for the GMAT, but I'd imagine if you weren't familiar with them, this question could be time consuming, since using both Statements, there are a lot of numbers to think about.
While perfect numbers are very spread out (there are only four of them less than 10,000), there are two different ones less than 30:
6 = 1 + 2 + 3
28 = 1 + 2 + 4 + 7 + 14
so the answer to this question is E.
While perfect numbers are very spread out (there are only four of them less than 10,000), there are two different ones less than 30:
6 = 1 + 2 + 3
28 = 1 + 2 + 4 + 7 + 14
so the answer to this question is E.
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