Question

two US coins that total 55 cents in value? one is not a nickel.

Answer 1

A coin known as the half-dime was minted in four different series, between 1794 and 1879

http://en.wikipedia.org/wiki/Half_dime

Answer 2

a 50 cent coin and a nickel

one of those is not a nickel!!!

Answer 3

Lawyers.