What is the value of a state quarter with Washington on heads and on reverse struck with Jefferson nickel l heads?

A state quarter featuring George Washington on the obverse and a Jefferson nickel design on the reverse is considered a mint error. Such coins can have significant collector interest, and their value can vary widely based on demand, rarity, and condition. Generally, these error coins can be worth anywhere from a few dollars to several hundred, depending on the specifics of the error and the market at the time. It's advisable to consult a coin expert or a recent price guide for a more accurate valuation.