Quadri-, quadru-, quadr-is a Latin prefix related to the verb quadrare âto make squareâ, quadratus âsquareâ etc. Quad is simply an English shortening of quadrangle, quadruplet etc. So quadri-and quad are actually the same word.
The Washington state sales tax rate is 6.5% , and the average WA sales tax after local surtaxes is 8.89% 1  . Groceries and prescription drugs are exempt from the Washington sales tax. 2  Counties and cities can charge an additional local sales tax of up to 3.1%, for a maximum possible combined sales tax of 9.6%.
With state gas taxes now up to 44.5 cents a gallon, adding in the current federal gas tax of 18.4 cents, the total per gallon gas tax in Washington is now 62.9 cents. The state increase was part of a $16 billion, 16-year transportation revenue package approved by the Legislature and signed by the governor earlier this summer.