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How many multisets of three positive integers have a mean of 9, a median of 11 and no mode? A multiset allows multiple instances for each of its elements. For example {1,2,2} and {2,1,2} are the same multiset.
Reminders:

• The Mean is equivalent to the average.
• The Median is the middle value when values are sorted by size.
• The Mode is the most often occurring value and is not set if no value is repeated.
1
20
6
27
16
11
4