Difference between revisions of "2016 UNM-PNM Statewide High School Mathematics Contest II Problems/Problem 6"
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== Solution== | == Solution== | ||
− | + | We can plug in the function 4 times. We get that | |
+ | <math>a_2 = 2+0+1+6+2+0+1+6 = 18</math> | ||
+ | <math>a_3 = 1+8 = 9</math> | ||
+ | <math>a_4 = 9</math> | ||
+ | <math>a_5 = 9</math> | ||
+ | So the answer is <math>\fbox{9}</math> | ||
== See also == | == See also == |
Revision as of 20:01, 6 August 2023
Problem
For a positive integer let be the sum of the digits of . For example, , while . Let and define
Find .
Solution
We can plug in the function 4 times. We get that So the answer is
See also
2016 UNM-PNM Contest II (Problems • Answer Key • Resources) | ||
Preceded by Problem 5 |
Followed by Problem 7 | |
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 | ||
All UNM-PNM Problems and Solutions |
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