### BARS::15 Miles From Mitchell Caverns in California

This road sign is in the Mojave National Preserve.

+--------------------------+
| Campgrounds              |
|   Hole In The Wall    20 |
|   Midhills            28 |
| Mitchell Caverns      15 |
+--------------------------+
the numbers are:  15  20  28

BARSfunc math:  spf(15) + 20 = 28
* spf(n) = the sum of the prime factors of n
* spf(15) = 3+5 = 8

BARSfunc rsAgeEval:  15 + spf(20) + 28 = 52
* RoadHacker was 52 years young when he found this road sign.
* spf(20) = 2+2+5 = 9

off-by-one rsStateEval:  15 * cuberoot(28 - 20) = 31-1
* California was the 31st state admitted to the Union.

BARSfunc off-by-one rsAgeEval:  20 + reverse_digits(28 - 15) = 52-1
* MathBabbler  was 52 years young when he found this road sign.
* reverse_digits(n) = the digits of n reversed
* domain:  n must be a prime number
* 28 - 15 = 13 and 13 is prime; reverse_digits(13) = 31

BARS::15 Miles From Ivanpah Road in California has the same numbers as this BARS.

Creator: Gerald Thurman [gthurman@gmail.com]
Created: 20 March 2010