Here's another riddle, I just thought this one up:
In base x, a number is 10101. The same number is 273 in base x+6
What is x? (ie, the base of the first number)
To change both sides into base 10:
Collecting same degree variables together, and factorizing
x=4 is one solution. The other solutions are -ve and fraction, so not suitable for a base.
Edited by brhan, 04 March 2008 - 11:36 PM.