Legal adult marijuana sales began in Nevada on Saturday, making it the fifth state in the nation to establish a regulated marijuana market for adults. Beginning at 12:01 a.m. PT, adults 21 and older with a valid ID will be able to purchase up to one ounce of marijuana or one-eighth of an ounce of marijuana-infused edibles or concentrates from licensed marijuana retail outlets. Retail marijuana sales will be subject to a 10 percent sales tax, which state officials estimate will generate more than…