1959 AHSME Problems/Problem 18
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Problem 18
The arithmetic mean (average) of the first 
positive integers is:
Solution
The sum of the first positive integers is the same as the nth triangular number, which can be expressed as 
. Since the question is asking for the arithmetic mean, the whole sum is divided by , thus giving us 
, which then simplifies to 
See also
| 1959 AHSC (Problems • Answer Key • Resources) | ||
| Preceded by Problem 17 |
Followed by Problem 19 | |
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