These road signs were found heading east on US Hwy-136 in Illinois. The road sign math was discovered while working on the final POTW for the Spring 2006 semester.

The signs say...

+--------------+ | San Jose 2 | | McLean 25 | +--------------+ +--------+ +-------+ | East | | Speed | | US 136 | | Limit | +--------+ | 55 | +-------+the numbers are: 2 25 55 136 the math is: sqrt(sqrt(136 - 55) - sqrt(25)) = 2 observe... 136 - 55 = 81 sqrt(81) = 9 sqrt(25) = 5 sqrt(9 - 5) = sqrt(4) = 2 sum_prime_factors(55) = 16 sum_prime_factors(136) = 23 the numbers are: 2 25 16 23 the math is: sqrt(2 * sqrt(sqrt(16))) + 23 = 25

**Creator:** Gerald Thurman
[gthurman@gmail.com]

**Created:** 30 April 2006

This work is licensed under a Creative Commons Attribution 3.0 United States License.