### BARS::Lots of Highway Signs on Route 66 in Flagstaff, Arizona

These highway signs are along Route 66 (Business I-40) in Flagstaff, Arizona.

The highway signs say...

```   +----------------+
| To East   I-40 |
| To North US-89 |
| East    US-180 |
| Arizona  US-66 |
| Business  I-40 |
| To South  I-17 |
| To West   I-40 |
+----------------+
```
```   the numbers are:  17  40  40  40  66  89  180

the math is:  mode(17, 40, 40, 66, 89, 180) = 40

off-by-one math:  (180 % 89)^(40 % 17) + 180 % 89 + 40 / 40 = 66+1

rsAgeEval:  66 + 40 - 40 - (180 % 17) + sqrt(89 % 40) = 59
* RoadHacker was 59 years young when he found these highway signs.

rsStateEval:  180 % 66 + 40 % 17 - sqrt(89 - 40 - 40)! = 48
* Arizona was the 48th state admitted to the Union.

rsHwyEval:  median(17, 40, 40, 40, 66, 89, 180) = 40
* This highway signs are on Business I-40

off-by-one rsAgeEval:  180 % 66 + 40 % 17 + sqrt(89 - 40 - 40)! = 59+1
* RoadHacker was 59 years young when he found these highway signs.

...playground...

180 % 66 = 48;  180 % 89 = 2;  180 % 40 = 20;  180 % 17 = 10
89 % 40 = 9;  66 % 17 = 15;   40 % 17 = 6

180, 66, and 40 are composite numbers

* spf(n) = the sum of the prime factors of n;
domain: n must be a composite number
...spf(180) = 2+2+3+3+5 = 15
...spf(66) = 2+3+11 = 16
...spf(40) = 2+2+2+5 = 11

17 and 89 are prime numbers

* sum_digits(n) = sum the digits of n
domain:  n must be a prime number
...sum_digits(17) = 8
...sum_digits(89) = 17

* mult_digits(n) = product of the digits of n
domain:  n must be a prime number
...mult_digits(17) = 7
...mult_digits(89) = 72

* reverse_digits(n) = the digits of n reversed
domain:  n must be a prime number
...reverse_digits(17) = 71 (71 is prime)
...reverse_digits(89) = 98
```

Creator: Gerald Thurman [gthurman@gmail.com]
Created: 27 September 2016 