Find number abc

There were eleven people hanging onto a rope that came down from a plane. Ten were blonde, and one was a brunette. They all decided that one person should get off because if they didn't, then the rope would break and everyone would die. No one could decide who should go, so finally the brunette said, "I'll get off." After a really touching speech from the brunette saying she would get off, all of the blondes started clapping.
(Problem solved.)