### BARS::Railroad Track Signs in Kansas City, Missouri

These railroad signs are at Union Station in Kansas City, Missouri.

```   +------------+ +------------+
| Track   30 | | Track   29 |
| Location 3 | | Location 3 |
+------------+ +------------+
```
```   the numbers are:  30  29  3  3

--- these equations were found on the train ---

the math is: 30 - 3 / 3 = 29

rsAgeEval:  30 + 29 - 3 / 3 = 58
* MathBabbler was 58 years young when he found these signs.

rs42Eval:  29 + 30 / 3 + 3 = 42
* 42 is the "Answer to Life, the Universe, and Everything"

rsCardinalityEval:  (30 - 29 + 3)! / 3! = 4
* There are four numbers in these signs.

off-by-one rs37Eval:  29 + 30 / 3 - 3 = 37-1
* Why rs37Eval? 37 Heaven @ http://thirty-seven.org

--- equations found after the train ride ---

rsStateEval:  ((30 - 29) + 3)! / 3! = 4
* There are four numbers in these signs.

rsStateEval:  (((30 - 29) + 3)! / 3!)! = 24
rsStateEval:  30! / 29! - 3 - 3 = 24
* Missouri was the 24th state admitted to the Union.

BARSfunc rs42eval:  30 + sum_digits(29) + 3 / 3 = 42
* 42 is the "Answer to Life, the Universe, and Everything"
* sum_digits(n) = sum the digits of n
domain:  n must be a prime number
* 29 is prime; sum_digits(29) = 2+9 = 11
* 30 + 11 + 3 / 3 = 42

BARSfunc rs42eval:  30 + mult_digits(29) - 3 - 3 = 42
* 42 is the "Answer to Life, the Universe, and Everything"
* mult_digits(n) = product of the digits of n
domain:  n must be a prime number
* 29 is prime; mult_digits(29) = 2*9 = 18
* 30 + 18 - 3 - 3 = 42

BARSfunc off-by-one rsAgeEval:  reverse_digits(29) - 30 - 3! + 3 = 58+1
* MathBabbler was 58 years young when he found these signs.
* Note: MathBabbler was older than 58 1/2. This would not have been
an off-by-one if found four months later.
```

Back in July of 2010 MathBabbler thought Kansas City Union Station was in Kansas. {BARS::Railroad Track Signs in Kansas City, Kansas}

Creator: Gerald Thurman [gthurman@gmail.com]
Created: 12 January 2016