Problem:
How many different integers can be expressed as the sum of three distinct members of the set ?
Answer Choices:
A.
B.
C.
D.
E.
Solution:
Each number in the given set is one more than a multiple of 3 . Therefore the sum of any three such numbers is itself a multiple of 3 . It is easily checked that every multiple of 3 from through is obtainable. There are multiples of 3 between 12 and 48 inclusive.
The problems on this page are the property of the MAA's American Mathematics Competitions