How do you escape % when formatting a string?

[erikcw]

Hi,

I'm trying to format a string like so:

string = "You have a 75% chance of success with %s, don't use %s" %(a,
b)

This gives me:
TypeError: not enough arguments for format string

I've tried 75\%, but that doesn't seem to help.  What am I missing?

Thanks!
Erik